I created a WebPart in Visual Studio 2010 and made the necessary changes to make it work in MOSS 2007. The webpart was working just fine, but I had to remove a couple webparts from the project, so I deactivated, retracted, removed then reinstalled the webpart and now I get this error: "Incompatible Web Part markup detected. Use *.dwp Web Part XML instead of *.webpart Web Part XML."
It was working just fine with the .webpart file, why is it now looking for a .dwp file?
During the removal of the webpart is there another step that I need to do to make sure it was COMPLETELY flushed out? It was gone from Central Admin -> Solution Management, the WebPart Gallery, etc.