I have the sit down 18 and have had issues. Mine is arriving home today after being sent back to the factory for a fix. If it isn't fixed to my satisfaction I think I'm going to have a meltdown and see about getting a new machine.
I heard that they had some issues in the factory (heard from a dealer, not from a TL rep). I wonder if your machine was in the same lot as mine :'(
I love my Lizzie but I don't like it when it doesn't work.