Hello! I decided to try to upx all the .exes and .dlls in the cygwin distribution to save space, and found the following problem. The error occurs with the "captoinfo.exe" I have (which I have uploaded to http://www.bubblescope.net/captoinfo.exe in case the version online changes, if anyone wants the source feel free to e-mail me and I'll send it to you compress simply using: upx captoinfo.exe then both upx -t captoinfo.exe (test archive) and upx -d captoinfo.exe (decompress archive) both fail. I am using upx 1.24w -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/