Not sure if this was suggested, as I am jumping in on the last page.....
Is there a professional long-armer in your area that you can have come out and
look at your machine? Having a professional look at it first hand may
be able to tell you right away if the machine is the issue, or give you some pointers.
When I am frustrated and at my wits end, having someone else look at it really helps.
Just a thought...