Cannot get rid of the error in the formula

Hello,

I'm using CR 2008 with Visual Studio 2008.

I have a strange problem here. I have a formatting formula that started giving me some errors, and I cannot get rid of it. Even if I remove this formula completely and delete all temporary CR files from the Temp folder - I'm still getting the same error from this function that doesn't exist anymore.

What could be the problem?

Thank you.