sudden error: "proc magic mismatch detected"

Hi,

I'd been using Cygwin on my PC w/o problems (for about 4 months),
until yesterday night. Today morning I get this error...

$ startx
C:\cygwin\usr\X11R6\bin\xinit.exe (2556): *** proc magic mismatch detected -
0x19C16FB6/0xD079E02.
This problem is probably due to using incompatible versions of the cygwin DLL.
Search for cygwin1.dll using the Windows Start->Find/Search facility
and delete all but the most recent version.  The most recent version
*should* reside in x:\cygwin\bin, where 'x' is the drive on which you
have installed the cygwin distribution.  Rebooting is also suggested
if you are unable to find another cygwin DLL.

If some has a clue as to how to fix this, please lemme know.  I've
reinstalled cygwin from a ISO image (which was used to install my
previous setup as well).

thanks,
bd