I have two cloth objects, a shirt and pocket. I select the verts on the pocket, shift-select the shirt, then Constraints->Cloth. Nothing. No error message. There is a constraint node, but no little square icons in the display. play and pocket falls to the ground. This is driving me nuts. What am I doing wrong?

-actually, mesh constraints don't work either, for shirt or pocket.
Shirt and pocket were both imported 3ds files that I used "Create Cloth Object" on, if it matters. (3dsImport.mll from bonus tools)

-also, I have pants in the same scene that have constraints and work fine.