FIX: The IDE stops responding when you modify C# code in Visual Studio 2005
It seems that the VS team are working hard on fixing the issues with Visual Studio. Just received this KB Alert by Scott Cate (the link is not working currently) and the email contains a link to a fix for this ‘The IDE stops responding when you modify C# code in Visual Studio 2005’. Not sure what does fix, but maybe it has something to do with what I experienced randomly with the IDE.
By the way check also this Microsoft document where you can find some answers to issuess with VS 2005.