I do it all of the time, but I also make some ridiculously intense back-ups before I do. It is ALWAYS risky doing this, but with good backups, you can always revert back. If something goes wrong, the quickest fix is to over-write the dll's with the old one's. I don't remember for sure, but I THINK that the dll's may have different names now, so if that's the case, your projects wouldn't load them properly. If that happens, rename the dll's and xml's to the old name and things SHOULD be ok.....But like I said, BACK UP YOUR NEBULA INSTALLATION FIRST!!