I got a IMEI locked flashplayer for my nokia 7610 phone, installed it and
everything was fine. After making a factory reset on the phone, I installed it
again and it wouldn't work-giving me the above-mentioned message ( invalid
license ). I had to remove the player - reset the phone - install it and reboot
again in order for it to work. Is it a player fault or just bad karma before
the contest ?

It's karma =) I've got very often problems like this.

Good Luck man, you'll do it!