User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_4; en-us) AppleWebKit/533.18.1 (KHTML, like Gecko) Version/5.0.2 Safari/533.18.5 http://www.mono-project.com/DllNotFoundException explains that the mono runtime searches the current working directory for DLLs. This opens a serious security hole. Malicious code can be given the same name as a DLL and left in a directory the user might visit. Also, it means that no mono application can safely set the current working directory. Microsoft themselves addressed this issue in Windows http://msdn.microsoft.com/en-us/library/ms682586(v=VS.85).aspx It's a well known "dummies" question for Unix why you must not have "." on your path http://www.unix.com/unix-dummies-questions-answers/22806-why-bad-idea-insert-dot-path.html Mono is exposing users to these same old hat problems. (As a related problem, many mono programs seem to *assume* that they will be run with the CWD set to their installed directory, and break if it isn't.) Reproducible: Always Steps to Reproduce: 1. 2. 3.