Unable to close Visual Studio 2008

I ran into an issue with not being able to close Visual Studio 2008 today.  My Visual Studio 2008 solution opened and work fine but then when I tried to close it, Visual Studio would just freeze up.  Something was going on since the processor was saying about 25% usage or so and the mouse was blinking back and forth between the wait cursor and the default arrow but no matter how long I waited, Visual Studio 2008 would not close (it definitely looked like it was stuck in a loop doing something while trying to close down). 

I was able to open and close another Visual Studio 2008 solution without any problems so this confirmed it was something specific to the this solution. 

After trying a couple random things (such as closing all files, removing a reference, etc.) I tried deleting the Visual Studio Solution User Options .suo file.

Deleting the file solved the problem!

So if you are ever in the same situation consider a corrupt .suo file to be the problem.