I've been wondering the same thing, although mine haven't folded up entirely. What happens is that one spot on the backside of either one looks like its pinched in one little area. I've been at 3/4" for well over a year, and just recently slid in a pair of 13/16" glass single-flairs with no problems at all. Hell, if I weren't apparently allergic to o-rings, I'd wear them as much as I could.
Anywho, I figured that my lobes being a little more stretched out was the cause of this little pinching/folding in one spot, and forgot about it. Reading this post, I'm reminded that someone mentioned on here that earskins don't really give the support that other, more solid plugs do, and therefore allow whatever minor shrinkage may occur. BUT, my 13/16" and my 3/4" plugs go right in, no problem.
Enough of my rambling...just throwing my .02 in, seein' what y'all think.