Not long ago I sold my Sapphire 830 and now wish I hadn't. I had it set up with the Fab-u-Motion w/cruise control and it was awesome. I still have a Designer SE and LOVE, LOVE, LOVE it! I have a Rose and took it to someone other than an authorized Viking dealer for annual cleaning/servicing. BIG mistake; found out from my Viking dealer that the longer screws were put back in the wrong place and the screws broke the housing on the transformer! NEVER take a Viking to anyone other than an authorized dealer. As for the bouncing bobbin, have you tried 'bobbin genies'? I use those little teflon rings for everything and all my machines love them whether I'm FMQ or embroidering. Lastly, what kind of thread are you using? It really does make a huge difference. Some have a ton on lint and others have almost none. 90% of the time I use Bottom Line thread in my bobbins and have not had any issues with it. Hope this is helpful info.