cygwin: starting cygwin gvim from windows program (e.g. outlook) report "cygwin1.dll is missing"

folks/experts:
I just successfully recompiled vim with GUI support under cygwin.
so now gvim is OK if I launch it from cygwin terminal (yes I have X running)
then I'm trying to make it the default text editor for my window7 
application
(like outlook, to open attachment), but then I got a dialog saying:
"the program can't start because cygwin1.dll is missing from your computer.
Try installing the program to fix this problem."
the same thing happened when I try launch gvim from a dos terminal.
is there any known solution for this?
I did some research but can't solve it.
thanks in advance.

regards
ping