uncaught exceptions in setup

[Yitzchak Scott-Thoennes]

I've downloaded the new setup (2.510.2.2) and am trying to run it and
getting uncaught exceptions like:

Fatal Error: Uncaught Exception
Thread: DialogProc
Type: 9Exception
Message: Package validation failure for
file://C:\setup\cygwin/http%3a%2f%2fmirrors.rcn.net%2fpub%2fsourceware%2fcygwin/release/x11/fontconfig/libfontconfig-devel/libfontconfig-devel-2.2.2-1.tar.bz2
AppErrNo: 1

I would really prefer not to have to rename things I've already downloaded
and installed just to download new stuff.