OK,
I made it. I installed 3.00 Alpha3, got the rebuild problem, synched and now it is working great. So far.
Hoping that is is of some help:
I updated Emplode to 2.10 . Tried to upograde the player sw and failed. Tried again with emplode 2.00, adn failed again. Then realized the upgrade.exe had not been changed. I so tried to upgrade starting upgrade.exe directly, without having emplode running, and I succeeded.
I got the rebuild problem, as I said. So I started emplode 2.00 again, which started to synch automatically. After it had done, I synched manually once more. Problem solved.
Now I am wondering whether I should try or not emplode 2.10.
I enabled crossfading. In a while I'll go and test if it works and if the radio+rds works. If so, I'm happy. Really!