The brown trim edges on our Westy are also shrinking back.  I don't notice
any difference in the summer or winter but where we live is humid all year
long.  I agree with whomever said it was probably the humidity getting into
the particle board.  I'm not planning to do anything about it, too many
other things I have to do to the van.

Wendy & John
'85 Westy,   "S-CAPE"