I've just come on board at a new mining organisation in Perth, WA called CITIC Pacific Mining as the Senior SharePoint Consultant. As with all new client sites, when you rock up it's interesting to see how different everything is. Especially as this project started over 18 months ago when MOSS 2007 was extremely new and documentation and the community was no where near its saturation now.

I came across an error where I couldn't open a Visual Studio 2005 Project File.  The error message stated that 'The Project type is not supported by this installation'. And then in the Solution Explorer states 'The project flie cannot be loaded.'. 

Fortunately thanks to Google I found the solution to this in this forum thread on MSDN off this article. Basically I removed the <ProjectGuidType> element from the .csproj file, it hasn't recreated a new element once I've opened the project file but it all seems to work fine and dandy!

<ProjectTypeGuids>{9E5D3E2D-E4E2-418e-8D80-2F0DA9A94F9A};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>

Reading further in on this thread, it looks like basically someone was using Visual Studio 2008 beta and didn't realise that it would cause an issue with people using the SOE Visual Studio 2005! The pains of playing with new toys!