I had a similar issue with my Janome 7700. I was using old thread and and universal needle on batiques, that was my issue. So I would say:
1) Try a needle from a different pack incase it was a quality control issue on the run of needles.
2) Try a different thread
3) If you have leftover fabric, put together a little practice sandwich and see if you are having the same issue. If you don't, compare what is different between the two.
Hope that helps. I know these issues can be so frustrating when you are on a deadline.