Windows 7, RC1.
After installing RC1, I uninstalled 2 or 3 old beta versions.
Today when I double-clicked a VPW file from Explorer, it prompted me for which application to use to open it - even though Explorer listed the "Type" as Slickedit.
Then in "Open With", I used "Browse" to find the RC1 version of VS.exe.
Even though I found it, Explorer wouldn't accept it - no error, it just wouldn't work.
From Tools > Options > File Options > Associate File Types I removed the association for VPW, then put it back, and now things work as they should.
Seems like uninstallation does something bad.