Slow PG after upgrade to 8.2.9!!

I hope someone can urgently help. I was running 8.2.3 with a lot of
pleasure and no-nonsense. Very fast and delightful database that had
me singing paeans.

But I upgraded to 8.2.9 this morning and have had a major slowdown of
the DB processes. How do I begin to test what is going wrong?

I checked the log files and there are "LOG:  duration: 84533.845 ms
statement: " type errors messages for the simplest of queries that
call the indexes into question.

Nothing has ben changed on the db or in the conf files other than just
the RPM upgrade!

The SELECTs are taking about 85 seconds and the main INSERT to a table
(no binary blob or anything, just usual data!) is taking about 145
seconds sometimes.

How can I begin to diagnose what is wrong? Has there been a major
change to some CONF variables between versions 8.2.3 and 8.2.9 that I
should look at?

Thanks for any pointers or direction!