Right mouse button not working in C# editor

Question

I happen to be using VS2008 but I suspect that the issue is not version specific.

When editing C# code the right button context menu does not work. It is only in the C# editor. Every place else around Visual Studio it works fine. I have seen it to work intermittently when I clicked in a parentheses at the end of a line. I was making some adjustments to the text editor and I suspect I may have checked or unchecked some option and did not realise the consequences.    

I have GhostDoc installed, is there anyway that would effect it? It is disabled now.

I tried Import and Export Settings Wizard and selected the option to "Reset all Settings" but that had no effect.

 

Thanks

Joseph