you could try rolling the portion your not working on and use quilt clips. You could roll each area around the hoop so that portions not being quilted just stay in a roll.
they sell them for using when machine quilting with a regular sewing machine. Some use bicycle clips (for holding pant legs close to the leg)
Here is a picture of a quilt clip (one of several styles)
[TABLE]
[TR]
[TD][/TD]
[TD]Quilt Clips-Full Size
4 full size (3" round) quilt clips. Holds rolled quilt for machine quilting. Plastic, will not rust, stain or snag. Will not scratch machine or furniture.
70104 $4.95
Click on image at left for alternate view [/TD]
[/TR]
[/TABLE]