PostgreSQL crash on Freebsd 7

Hello.
I have problems with Postgres core dumping on FreeBSD7 (RELENG_7)

Here is backtrace from gdb postgres postgres.core:

(gdb) bt
#0 0x485dc277 in kill () from /lib/libc.so.7
#1 0x485dc1d6 in raise () from /lib/libc.so.7
#2 0x485dadda in abort () from /lib/libc.so.7
#3 0x0824c075 in errfinish ()
#4 0x0824c8b1 in elog_finish ()
#5 0x081c9184 in s_lock ()
#6 0x081c8d48 in LWLockAcquire ()
#7 0x081c61ec in LockAcquire ()
#8 0x081c4289 in LockRelationOid ()
#9 0x080938fc in relation_open ()
#10 0x08096d5a in index_open ()
#11 0x08096139 in systable_beginscan ()
#12 0x08134f10 in RelationBuildTriggers ()
#13 0x08245d4d in RelationCacheInitializePhase2 ()
#14 0x08256af0 in InitPostgres ()
#15 0x081cfd13 in PostgresMain ()
#16 0x081a90ec in ClosePostmasterPorts ()
#17 0x081a9ea7 in PostmasterMain ()
#18 0x0816912f in main ()

Extract from dmesg:
pid 30622 (postgres), uid 70: exited on signal 6 (core dumped)

Nothing interesting in other logs.

I run FreeBSD 7.0-BETA1 on Dual-Core AMD Opteron(tm) Processor 2216
(2394.01-MHz 686-class CPU) with ULE scheduler
PostgreSQL 8.2.5

I can't find what triggers this behavior (it started core dumping
after upgrading from FreeBSD 6.2)

Anyone have solution for this problem?

Michael