Ugh! (Part 2 of an ongoing saga..)

[whisperkit]

I posted recently about my sewing machine suddenly starting to drop stitches in lycra. After a long afternoon of cleaning, needle-switching, tension fiddling and testing, I got it to limp through with a high enough picked-up stitch rate that it did the job. However, now I'm finding that it's doing similar on fleece. The annoying thing is, I've sewed fleece doubled, even quadrupled through this machine, and it's never complained once. It even seems to work fine on red fleece. But on the white variety I'm using, it drops right hand stitches all the time, on zig-zag or 3-stitch zig-zag. I'm starting to worry that my once-reliable sewing machine is starting to have Problems. I've tried opening it up for further cleaning, but whoever put it together in the factory did so with so much zeal that I can feel my screwdriver giving before the screws even think about loosening.

I'm really at a loss here. Why is my sewing machine suddenly doing this, when previously it worked fine? Do I need to take it in to someone to get it retimed or lubricated (or dump copious amounts of WD40 on the screws and pray, which may be cheaper). The frustrating thing is, on lining fabric (which I'm using as my control test) it still acts like nothing's the matter. It's just seemingly lost it's high tolerance for stretch & fleece materials.

There goes the outfit deadline, anyway. Ah well. :(

Any advice would be hugely appreciated.