On Thu, 01 Jul 2010 20:28:18 -0500, "Pete C."
wrote:

Next suspect after that is the two tank bolts and
the rubber washers that seal those. The tank washers could also result
in a leak that runs down the back of the toilet and could appear below.

Exactly. A toilet I fixed once was a very slow leak at the tank washer
bolts. Something as simple as bumping the tank, flushing it caused a
tiny leak from one bolt washer that had deformed.

The way I found it was reaching under the tank/bolts, feeling the
wetness.