How tight is your quilt rolled? It should not be drum tight, but actually quite loose. The rule of thumb is to be able to grab a finger that is pushed up from below.
You may need to adjust your tensions for frame quilting. Basically you want to loosen the bobbin tension as much as possible, then adjust the top tension. Although the following Youtube video is for longarms, it seems to apply to any machine used on a frame:
http://www.youtube.com/watch?v=Q1mRh...664A7&index=13
I attach the backing top and bottom, then lay the batting on the backing and sew across the top of the batting using a "channel lock". This basically means the carriage does not move forwards or backwards so you get a straight line. I do this on my Hinty by using a large black binder clip behind just one of the bearings on the carriage. If I can find the website with a picture of this, I will post it. Anyway, this is how I "float" the batting, as the batting bottom is not attached to anything.
Floating the top works in the same way. You stitch it to the batting/backing using a channel lock. (The purpose of the channel lock is to make sure you get a straight line.) To fully float the top, you do not attach the bottom to anything.
I personally had a disaster on my hands when I did a full float of the top. I do the above, but attach the bottom to one of the rails.
I absolutely could not stand to do all that pinning. I purchased long zippers on Amazon (the seller is on eBay also) and now zip my quilts on and off the frame. Found a couple of tutorials online that showed how to sew zippers to the leaders.