Vacuum and Hash Tables

Hi,

Currently, i'm helping out in a project testing the cache miss rates for
different buffer replacement policies. I've tried asking the postgresql
channel on IRC but was directed to this mailing list instead.

At the moment, i've replaced freelist.c with an implementation of the LRU
policy and test runs of this policy independant of the server appears to
show that it works as expected. I run into problems however, when i attempt
to initialise the template1. The code returns

vacuuming database template1... FATAL: shared buffer hash table corrupted

I suspect that this has something to do with the hashtables that i've used
in buf_tables.c and the vacuum. Can anyone point me to any resources that
might shed more light on this?

Incidently, the code base i'm using is version 8.0.4

Regards,
Joseph