Have them check out the plastic part where the screws are in the front of the machine. There is something about the 400 series that it is happening. I have both the 430 and the 440 and had to have the front cover replaced on both. It is quite pricey as it involves a lot of labor, but Bernina covers all expenses. However, here is the catch. The warranty that covers the replacement only is covered under the original owner! I found that out, when I took my 430 in to have it fixed and the warranty was in moms name. My wonderful Bernina Dealer, that I will be a customer for life, just filed it under mom's name. This is not enough to walk away from a great deal and a wonderful machine, as not every 400 series has this problem. Just talk to you dealer about it, and make sure it is still good before the year warranty wears out.