How old is your machine? There should be at least a 90 day service warranty -- as in 90 days of free service.
First thing to check when the "timing is out," is the needle. Replace it, so you know it's not bent. Then make sure the flat side is to the back, and pushed all the way up.
Sometimes what causes the timing to go out is running over those big "quilting" pins. If you have those, replace them with "patchwork" pins. They don't cause as much damage as those big "quilting" pins.
Another thing to check, is if your needle bar has forward/backward wiggle. The needle bar has to wiggle side to side. But if it wiggles forward and backwards, it was made very sloppy, and the timing will continue to go out, over and over again.