Fortify analyzer issue for an C# project

Hi there,

I have been struggling for sometimes with my C# project source code scanned with Fortity 4.30 over windows 7 server. I used both Fortify GUI and command "sourceanalyzer -scan myproject myproject.sln" to do source scan , the result were the same: there never scanned any c# .cs file, there are a few hundreds of .cs files in it's current & sub-folders. Where is the problem?

Thanks in advance.