BUG #3731: ash table "PROCLOCK hash" corrupted

The following bug has been logged online:

Bug reference:      3731
Logged by:          Daniel Cristian Cruz
Email address:      cruz@senai-sc.ind.br
PostgreSQL version: 8.2.4
Operating system:   Red Hat ES 4
Description:        ash table "PROCLOCK hash" corrupted
Details:

A few moments ago I got the following message, but didn't found any
reference on the internet (including lists).

Nov  8 13:50:56 SERVER postgres[18874]: [5-1] user=XXX,db=XXXPANIC:  hash
table "PROCLOCK hash" corrupted

The error showed after some query that where logged because were slow (more
than 5 seconds), in which they had a very big list of values in a NOT IN
clause (not sure if this caused the problem).

I don't know if this is a bug or not.