Well, I guess this a good a time as any for a first post... been lurking for months
In my experience the only time I've had a PTB filler stick to the atty is when it is almost dry (still a little liquid in the fold but none/little in the lower part of the filler). If your PTB filler is sticking when still wet I'd check how tightly you have it rolled. The center of the filler should be loose enough that the atty bridge can deform the center of the filler with out pushing the whole thing down; to loosen the filler while in the cart you can try pinching the center of the filler with a pair of tweezers and rotating the material in the opposite direction that it was rolled. The first few PTB fillers I made were horrible... a little experimentation with the top folds and rolls and you'll find what works best for you.