Hi Fredrik,
although I'm on Win7 I always run anything with admin rights. I also disabled the UAC on my machine. The registry key you mentioned is set and has two binary values, "Data" and "ssc2salt" and I guess one is supposed to contain the encoded registration.
I just opened µTonic again after looking in the registry and it was in demo mode again. I entered the reg details and the "Data" value changed.. I will keep track of it the next few weeks.
The odd thing is that it doesn't loose the reg always, for a few weeks everything is fine and one day it's gone out of the blue. I'm an IT professional and know my computer well

- µTonic is the only VST that does this, even Synplant doesn't seem to have that problem.
Btw. I would prefer if the reg data and config was written to a file anyway - though I'm on Win, I really hate the registry stuff.