I remember having a hard time with DrumCore when I tried it during the implementation of ReWire support in Podium. There were no uninstaller with DrumCore and I had to do a system restore in Vista to get rid of it. This time I downloaded and installed the DrumCore demo on my old laptop. I try to keep my development PC as clean as possible, so that excludes software that won’t uninstall easily.
I can confirm that I also get the “DrumCore ReWire error 666 (IsPanelAppLaunched)” error when I try to use DrumCore.
The Propellerheads source code comment for ReWire error 666 reads:
/* DLL error – call the cops! */
This leaves me with no clue as to what goes wrong.
Have you tried to contact the DrumCore developers? If you have the standard 200$ drumcore version, maybe they wouldn’t mind testing it in Podium for you?