I originally had a Tin Lizzie. I actually liked the machine just fine. Never had any tension issues, it sewed very well. This is how I set my tension:
https://www.youtube.com/watch?v=Q1mRhcquZTM
The issue I had was that the encoders were constantly malfunctioning. I eventually just learned to quilt in manual mode. The other thing I disliked was that it was on an older style frame without a dead bar. You had to lift the take up bar on both sides of the frame when you advanced the quilt. I traded it in on a HandiQuilter and have been very happy.
There may be a couple reasons why your tension goes out during quilting. Eyelashes on the back usually mean top tension problems:
1) When you thread the machine, make sure that the thread is firmly seated in the tension disks. If it's just caught in the edge, it could jump out after you get going. If your machine has a presser foot lever make sure it's up when you thread. Check the stitching every time you advance the quilt. If you see eyelashes, immediately look to see if the thread is still in the correct path. I have read of folks wrapping the thread around the tension disks twice to prevent this.
2) If the eyelashes are only on parts of the seam, then you may be going too fast on curves. Try slowing down.
Finally, there is a dedicated Tin Lizzie forum on Yahoo. You might want to join that for specific questions.