I just had this SAME problem last night.
I adjusted the needle where it was not pushed all the way into the socket. It needed to be a little lower than the socket allowed. but be careful how low you bring it, because i put mine a little too low and broke the needle.
Found out this morning that I need a different size needle.
Here is the thread from last night.
http://www.quiltingboard.com/t-139284-1.htm
Good luck.
Priscilla