Dont really know mate, can you render them off at all?? As that might help it out.
If it was me and I was going to show off my ncloth skills I think that I would have the cameras closer in, kinda with the camera going parallel to the walk to show off the cloth's movement and interaction, rarther then the whole shot as it is at the mo.
Cheers
Steve
"No pressure, no diamonds" Thomas Carlyle