There's an advice for the ones that have compiled the SF source code:

"Manually delete the StrataFrame DLLs from the GAC before installing the new version of StrataFrame. "

As it was my case, I tried to follow this, and got a message saying they were in use by an application, and I couldn't delete them. I did this after uninstalling SF, and even tried to re-start the computer. So I just recompiled the source again and carried on, everything is fine.

Cheers.