Thanks to those who replied to my earlier post.  All three replies 
mentioned the same thing.  I took off the vents, and looked at the 
drain hoses....both seemed to be unclogged at the ends.  So, what can I 
do next?  Is it possible that they're clogged at the point where they 
hook up to the water collecting tray?  I'm still having the problem.
It makes more sense to me that the clog is earlier in the hose than at 
the end, but maybe I'm not looking at it correctly.

Any advice will be appreciated.  Meanwhile, the engine's running great, 
so who am I to complain?

david