I was rewarded with full license (thanx again!

. Recently FForge started to behave weird: While I'm editing a filter and I want to save, suddenly it says that I can't save in the basic edition. I saved like a dozen times during that session with no problem.
When I enter the license details (which are now cleared) it says that the data is invalid.
Strangely enough, after reinstalling FForge, the name and serial is filled in automatically and the software functions as a full version. At least until it forgets the serial again.
EDIT: System: PaintShopPro X2, WinXP SP2, AMD Athlon 64 X2 3800+