Lew,
Thanks for the reply. I think you're right about over-cleaning it as it seemed to "seal up" more and more the longer it ran. In my defense, this thing was "gunky" (if that is a word). I'm talking pressure washer with a 0-degree tip dirty, and that still didn't get all of the gunk off...
I've owned an 18.5" WSM for about a year and I happened across a 22.5" WSM on CraigsList that I was able to get for $160 with the Weber cover. Since I paid $150 for my 18.5" WSM used on CraigsList, I felt that this was a pretty good deal. After a thorough cleaning (this thing was "well used"...