Hi all, Thanks for your all your replies. I went for managed C++ because I wanted to create a GUI very quickly - Windows Forms are ideal for this and they only work with managed code. Since then I have been busy re-writing the GUI in unmanaged, proper C++ in a new VS project using the Win32API (in the same VS2010 on the same machine). I'm happy to say that I am not experiencing the problems I had before and everything works as it should. Regards, Alan. _______________________________________________________ Unlimited Disk, Data Transfer, PHP/MySQL Domain Hosting http://www.doteasy.com