postgresql8.1 crushes on some inserts/updates in KOI8 encoding

postgresql server crushes on some inserts / upates statements.

log looks like this:
2005-11-16 20:48:58 MSK - : LOG: server process (PID 16010) was
terminated by signal 11
2005-11-16 20:48:58 MSK - : LOG: terminating any other active server
processes
2005-11-16 20:48:58 MSK - udaff : FATAL: the database system is in
recovery mode
2005-11-16 20:48:58 MSK - udaff : WARNING: terminating connection
because of crash of another server process

core backtrace :

#0 0x08079414 in slot_deform_tuple (slot=0x837dfe0, natts=10) at
heaptuple.c:1262
1262 off = att_addlength(off, thisatt->attlen, tp +
off);
(gdb) bt
#0 0x08079414 in slot_deform_tuple (slot=0x837dfe0, natts=10) at
heaptuple.c:1262
#1 0x0807955f in slot_getattr (slot=0x837dfe0, attnum=10,
isnull=0xbfffe5db "\001(ч7\bdш7\b\001") at heaptuple.c:1367
#2 0x080bb7c0 in FormIndexDatum (indexInfo=0x837de28, slot=0x837dfe0,
estate=0x837dad8, values=0xbfffe62c, isnull=0xbfffe6ac "") at index.c:962
#3 0x08130f12 in ExecInsertIndexTuples (slot=0x837dfe0,
tupleid=0x8382b0c, estate=0x837dad8, is_vacuum=0 '\0') at execUtils.c:925
#4 0x08129ac5 in ExecutorRun (queryDesc=0x837d6f8,
direction=ForwardScanDirection, count=0) at execMain.c:1437
#5 0x081a8471 in ProcessQuery (parsetree=Variable "parsetree" is not
available.
) at pquery.c:174
#6 0x081a993a in PortalRun (portal=0x837b520, count=2147483647,
dest=0x834e428, altdest=0x834e428, completionTag=0xbfffe918 "") at
pquery.c:1076
#7 0x081a582f in exec_simple_query (
query_string=0x8355d08 "INSERT INTO ra_documents ( title, author,
author_id, body, preview, ear, keywords, parent, dt ) VALUES (
'Cyринамская пипа', 'rak_rak', '2342', 'Мама Лены безумно любила
дерматологические эксперименты"...) at postgres.c:1014
#8 0x081a67e2 in PostgresMain (argc=4, argv=0x8304f00,
username=0x8304ed8 "postgres") at postgres.c:3168
#9 0x081803b6 in ServerLoop () at postmaster.c:2854
#10 0x081811e1 in PostmasterMain (argc=5,
argv=0x8303170) at
postmaster.c:943
#11 0x08146170 in main (argc=5, argv=0x8303170) at
main.c:256

table structure (s.sql) and query (q.sql - koi8-r encoding) to reproduse the problem are
attached. database encoding KOI8.

postgresql version 8.1
Architecture: i686
Kernel: Linux 2.6.11 (2.6.x actually)
Linux distributions: debian (sid, unstable), gentoo

cross-posted to http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=339527

WBR,
Alexey Bestchekov