My Lizzie will sew anything I put in it except the cheap serger thread from the discount stores. Here is the link to the TinLizzie yahoo group, it is a VERY activ group and TONS of help:
http://groups.yahoo.com/group/TinLizzieLongarm/
When you say "took it down", what do you mean by that? Also, when sewing curves, don't go faster than your machine can go.
When you load your bobbin it the bobbin case, rest on it's side on your open palm and pull the thread. It should just lift it up, if the bobbin doesn't move, then it's too loose, if it lifts it off your hand it's too tight.
Also here is s youtube video:
http://www.youtube.com/watch?v=Q1mRh...1E7B7591A8F559
A longarm is not like a DSM, you will need to adjust bobbin and top tension from time to time.
Also, do you have the correct size needle for the machine/and the thread you are using?