postgres.exe 100% CPU but no I/O

Hi all, I recently noticed that I have a postgres.exe process running at
100% CPU but is not doing any I/O.  This is fresh off of starting the
service.  This is a local db so I am the only one using it and it will
do this even if I do not have any queries running.  I have let it run
for about 2 days (not running any queries) but it never stops so I
figured I'd ask for some advice.  I upgraded to 8.2.11 about a month ago
and haven't had any issues so this seems to be a recent development
within the last week.  I guess my question is how should I go about
tracking down the cause of this running wild?  I'm running Win XP64 SP2,
Postgre 8.2.11.

Thanks in advance for any pointers.
Bob