Just wondering if anyone that has bought the 3660 has had a problem with the extension tops not being perfectly flat with table top. Mine seem to go up on the outer edges of both extensions. Has anyone shimmed theirs? I have a machinist background and I like for things to be very close. I have a few other adjustments to make everything as close as possible. I think I am going to like this TS3660 but who wouldn't coming from a Craftsman 10'' direct drive 10 years old.