oops, a code post - should have done that without being asked...
Actually the most recent issue was when trying somebody else's control:
(I believe it is a fairly small & clean example with a aspx in the zip)
I have had this problem elsewhere - but I forget which project I had that issue in so I'll suggest try out this link and the problem is probably the same in my other situation.
I could have bugged the author of that other code about the issue - but then I wouldn't have thought of the opportunity to give kudos about the book