Tvheadend

is this running on a virtual machine? (I see dom0 as the host name)

I booted without xen. Couldn't get the tv-card working in xen. So not virtual machine.
Linux dom0 3.0.0-12-server #20~lucid1build2-Ubuntu SMP Thu Oct 13 17:40:47 UTC 2011 x86_64 GNU/Linux

Could you add gdb information?
https://www.lonelycoder.com/redmine/projects/tvheadend/wiki/Tvheadendcrash

[DEBUG]:dvb: "/dev/dvb/adapter0" tuning to "Teracom_Mux_4: 706,000 kHz" (Initial autoscan)
[DEBUG]:dvb: "Teracom_Mux_4: 706,000 kHz" on adapter "DiBcom 3000MC/P 0", status changed to Bursty FEC
[INFO]:dvr: "Dox: Knuckle" on "SVT1" starting at Tue Jan 31 22:00:00 2012, scheduled for recording by "hans"
[INFO]:dvr: "Dox: Knuckle" on "SVT1" recorder starting
[New Thread 0x7fffea7cf700 (LWP 10115)]
[DEBUG]:dvr: Use (null) container
tcp_server: epoll_wait: Interrupted system call

Program received signal SIGSEGV, Segmentation fault.
0x0000000000427397 in dvr_rec_subscribe (de=0x7ffff00bb520)
at /tmp/buildd/tvheadend-2.12.99~pulse/src/dvr/dvr_rec.c:80
80 /tmp/buildd/tvheadend-2.12.99~pulse/src/dvr/dvr_rec.c: No such file or directory.
in /tmp/buildd/tvheadend-2.12.99~pulse/src/dvr/dvr_rec.c

(gdb) info reg
rax 0x0 0
rbx 0x7ffff00bb520 140737220687136
rcx 0x9 9
rdx 0x7ffff6b2ce00 140737332301312
rsi 0x0 0
rdi 0x4535b2 4535730
rbp 0x7ffff0010680 0x7ffff0010680
rsp 0x7fffffffe520 0x7fffffffe520
r8 0x7ffff7fe8740 140737354041152
r9 0x44cc55 4508757
r10 0x0 0
r11 0x206 518
r12 0x7ffff00bb628 140737220687400
r13 0x7ffff6b2dbe0 140737332304864
r14 0x12c 300
r15 0x44ccfe 4508926
rip 0x427397 0x427397 <dvr_rec_subscribe+215>
eflags 0x10206 [ PF IF RF ]
cs 0x33 51
ss 0x2b 43
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x0 0

(gdb) disassemble $pc-32,$pc+32
Dump of assembler code from 0x427377 to 0x4273b7:
0x0000000000427377 <dvr_rec_subscribe+183>: add %bh,0x7(%rdi)
0x000000000042737d <dvr_rec_subscribe+189>: xor %eax,%eax
0x000000000042737f <dvr_rec_subscribe+191>: mov $0x451e7c,%edx
0x0000000000427384 <dvr_rec_subscribe+196>: callq 0x404b30 <tvhlog>
0x0000000000427389 <dvr_rec_subscribe+201>: mov 0x10(%rbp),%rsi
0x000000000042738d <dvr_rec_subscribe+205>: mov $0x4535b2,%edi
0x0000000000427392 <dvr_rec_subscribe+210>: mov $0x9,%ecx
=> 0x0000000000427397 <dvr_rec_subscribe+215>: repz cmpsb %es:(%rdi),%ds:(%rsi)
0x0000000000427399 <dvr_rec_subscribe+217>: je 0x427410 <dvr_rec_subscribe+336>
0x000000000042739b <dvr_rec_subscribe+219>: mov 0x20(%rbx),%rdi
0x000000000042739f <dvr_rec_subscribe+223>: mov $0x1,%r8d
0x00000000004273a5 <dvr_rec_subscribe+229>: mov %r12,%rcx
0x00000000004273a8 <dvr_rec_subscribe+232>: mov %rsp,%rdx
0x00000000004273ab <dvr_rec_subscribe+235>: mov %r14d,%esi
0x00000000004273ae <dvr_rec_subscribe+238>: callq 0x412800 <subscription_create_from_channel>
0x00000000004273b3 <dvr_rec_subscribe+243>: mov %rax,0x100(%rbx)
End of assembler dump.

#0 0x0000000000427397 in dvr_rec_subscribe (de=0x7ffff00bb520)
at /tmp/buildd/tvheadend-2.12.99~pulse/src/dvr/dvr_rec.c:80
buf = "DVR: Dox: Knuckle", '\000' <repeats 15 times>"\340, ۲\366\377\177\000\000@β\366\377\177\000\000t\000\000\000\000\000\000\000@β\366\377\177\000\000t", '\000' <repeats 15 times>"\340, ۲\366\377\177\000\000\000\000\000\000\000\000\000\000\376\314D"
cfg = 0x7ffff0010680
PRETTY_FUNCTION = "dvr_rec_subscribe"
#1 0x00000000004256a5 in dvr_timer_start_recording (aux=0x7ffff00bb520)
at /tmp/buildd/tvheadend-2.12.99~pulse/src/dvr/dvr_db.c:707
No locals.
#2 0x000000000040541e in mainloop (argc=<value optimized out>, argv=<value optimized out>)
at /tmp/buildd/tvheadend-2.12.99~pulse/src/main.c:216
gti = 0x7ffff6b2ce00
cb = 0
#3 main (argc=<value optimized out>, argv=<value optimized out>)
at /tmp/buildd/tvheadend-2.12.99~pulse/src/main.c:441
c = <value optimized out>
forkaway = 0
pidfile = <value optimized out>
pidpath = 0x44cc9b "/var/run/tvheadend.pid"
grp = 0x7ffff6b2dbe0
pw = <value optimized out>
usernam = 0x0
groupnam = 0x44ccfe "video"
createdefault = <value optimized out>
set = {__val = {16386, 0 <repeats 15 times>}}
rawts_input = 0x0
join_transport = 0x0
confpath = 0x0
p = <value optimized out>
endp = 0x44cb55 "H\205\355t\034\061\333\017\037@"
adapter_mask = <value optimized out>
crash = 0

Hope that help. I think there is a problem with the tv-signal and that could be the cause of the problem.

I can confirm this crash. Everytime a recording is started tvheadend crashs with the same error.
The same thing happens if I open the "Digital Video Recorder"-Tab in the configuration section of the webinterface. All the fields of the form stay empty.
If i delete the dvr/config file I can open the DVR tab, but hitting "save" crashs tvheadend and the config file isn't created.

Feb  7 22:07:51 stefhess tvheadend[7773]: dvr: "Castle" on "kabel eins": Updated Timer
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: Signal: 11 in PRG: /usr/bin/tvheadend (2.12.99~pulse-4) [366e10633962afb9028fab466dce537872d2ba7b] CWD: /  
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: Fault address (nil) (Address not mapped)
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: Loaded libraries: /lib/x86_64-linux-gnu/librt.so.1 /lib/x86_64-linux-gnu/libdl.so.2 /usr/lib/x86_64-linux-gnu/libavahi-common.so.3 /usr/lib/x86_64-linux-gnu/libavahi-client.so.3 /lib/libssl.so.0.9.8 /lib/libcrypto.so.0.9.8 /lib/x86_64-linux-gnu/libpthread.so.0 /lib/x86_64-linux-gnu/libm.so.6 /lib/x86_64-linux-gnu/libc.so.6 /lib64/ld-linux-x86-64.so.2 /lib/x86_64-linux-gnu/libdbus-1.so.3 /lib/x86_64-linux-gnu/libz.so.1 /lib/x86_64-linux-gnu/libnss_compat.so.2 /lib/x86_64-linux-gnu/libnsl.so.1 /lib/x86_64-linux-gnu/libnss_nis.so.2 /lib/x86_64-linux-gnu/libnss_files.so.2  
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: Register dump [23]: 00007f4100056248 00007f4100056228 0000000000000007 0000000000000003 000000000237cfa0 00007f40f4ddd590 00007f40f4ddd610 000000000000001c 0000000000000000 000000000045014c 000000000237df40 0000000000000000 0000000000000000 0000000000000000 0000000000000000 00007f40f4ddd2d8 00007f40ffd495d1 0000000000010283 0000000000000033 0000000000000004 000000000000000e fffffffe7ffbfa17 0000000000000000 
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: STACKTRACE
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x420e4b
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x7f41002efc60
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x7f40ffd495d1
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: __strdup+0x16  (/lib/x86_64-linux-gnu/libc.so.6)
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x41ce2b
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x435956
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x407c7d
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x4083d5
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x4085d0
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x406a5d
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: ??:0 0x7f41002e6d8c
Feb  7 22:15:18 stefhess tvheadend[7773]: CRASH: clone+0x6d  (/lib/x86_64-linux-gnu/libc.so.6)
Feb  7 22:15:18 stefhess kernel: [50379.764159] tvheadend[7788]: segfault at 0 ip 00007f40ffd495d1 sp 00007f40f4ddd2d8 error 4 in libc-2.13.so[7f40ffcc7000+18a000]