8.0.0 on disk fails regress test, but on ram disk it is fine...

I'm preparing to upgrade our PostgreSQL installation from 7.3.5 to
8.0.0. I downloaded, configured, compiled, and did gmake check and
much to my surprise, 26 of the 96 tests failed.

Examination of regression.diffs shows that 1 of the failures is random
(and it is ignored) but 23 of the 26 errors are:

! psql: could not send startup packet: Broken pipe

Interestingly enough, if I load the source code onto a 1GB ram disk and
configure, compile and check it there, all 96 tests pass.

Hardware is RAID 1 using 2 disks with one additional disk as a hot
spare, dual 2.66 GHz Xeon processors with 2 GB of RAM. Operating
system is OpenBSD 3.6.

I'm a little leary of upgrading my PostgreSQL installation with those
kind of failure rates.

I'd appreciate any insight as to why so many tests would fail when run
on disk and pass when run in ram.

Thanks,

Jeff Ross