I had this problem today, too. I installed it (Win XP) under my user (Stefan) that has no administrative rights. So I right-clicked on the setup and executed it as admin with all privileges. After the installation was finished it started and I begun to configure it. Then I mixed two and an half hour to test it and wrote some things down (pros and cons reported later). At last I saved my session and collection and quit Cross. So after I finished mixing I wanted to test if this serial problem occures and so I started Cross again and what happende? I had to enter my serial. So I did and wanted to mix again but what happened? The collection was gone and Cross was blank. This is the point where there was a click in my brain
After the installation Cross was started as administrator. This is proven because the session data was stored in the admin account and when I wanted to open this data he lead me to my users account and so there was no data. So I copied this session data (*.mpx) to my user account with less privileges and opened this one. It worked and works. After I reopened Cross there was no question about the serial and I hope, that it will never again ask for it
If so I will report at once!
Maybe this helps some guys around. Don't know if this works on vista or Win7 :-(
Greetings,
Steve