strange segfault with 8.3.8 - Mailing list pgsql-hackers

hello,

from kernel log:

Dec  7 07:24:45 nsXXXXXX kernel: postgres[22481]: segfault at 7fda5e1d5000 ip 00007fda604553c3 sp 00007fffe41faf28 error 4 in libc-2.9.so[7fda603d1000+168000]

Dec  7 07:24:45 nsXXXXXX kernel: grsec: From XX.YY.ZZ.51: Segmentation fault occurred at 00007fda5e1d5000 in /usr/lib/postgresql/8.3/bin/postgres[postgres:22481] uid/euid:103/103 gid/egid:114/114, parent /usr/lib/postgresql/8.3/bin/postgres[postgres:29857] uid/euid:103/103 gid/egid:114/114

This is on 8.3.8, latest Ubuntu distribution, server under quite heavy load.

afterwards we had some corrupted pages ("ERROR: compressed data is corrupt").

any clues / directions welcome.