Originally Posted by mrs. fitz
Sounds like it could be a thread somewhere inside. A machine should be able to sew properly with many different brands of thread, even the cheap stuff. You might not want the cheapies on your work but the machine should adapt anyway.
What I've noticed with my machine is that using the cheaper threads (I bought some online I "thought" was a good deal) and they break very easily. So, I just go with a little better brand that my machine works well with and stick with it. I've also noticed that the cheaper brands tend to create more lint buildup which is why I like Connecting Threads cotton thread -- very low lint and little breakage.