Visual studio 2008 - Find in files : lists everything twice

Question

In VS2008, I have a web-site project. When I use find in files and search for a string, the find results window will list every occurence twice.

What could be causing this?

[EDIT]

Below is the screen capture from VS. I was searching for the work CommissionBucketProductID within my website project. Notice that each line is returned twice.

[EDIT2]

In response to your questions. I am only searching within the project, not the whole solution. I currently don't have these files under VSS, although they were in the past.