Unintended shutdown in postgres 7.4

Let me just say that I love all the work that has been done for postgres 7.4.
The information_schema is totally cool!

We've been seeing a problem where the database server will shutdown
unexpectedly. This generally happens when we are in the middle of importing
a large dump in .sql format from a mysql database (we're currently converting).

Interesting things in the log file are:

LOG: could not send data to client: Broken pipe
LOG: unexpected EOF on client connection
LOG: received fast shutdown request
LOG: aborting any active transactions
FATAL: terminating connection due to administrator command

However, nobody issued a "fast shutdown request". It just seems like the DB
died and stopped responding.

Has anybody else seen this before? Do you need me to gather any more data
on the problem?

Thanks,

Chad