I've got the same problem few weeks ago- suddenly Logic 7 stopped and asked for access code. so- at last in the morning I got that code from Apple support online, but that was nightmare all night long... Thanks God, I had that original installing CD's with challenge code.... :-))) With Logic 6 same story- there was offer to activize demos... And- I don't know, where are those mine original CD's... But, probably, if even I get them, seems, that there will not be support for Emagic product anymore... I am a user of Logic from 5th, with XSKey. Now- for music production I use L7, but for scoring L6, because in 7th- there are stil bugs for lyrics input in Latvian (Central EU). btw, lyrics in Logic 8 works fine again ,but for scoring me too- I prefer 6 or 7 (if without lyrics).
So- solution, that worked for me: I started those all demos, then after couple of weeks, I tryed to set my Mac's date few days erlier. Restarted, then open Logic6. I got message about shorteen of demo period for 7 days. I quited. Then set correct date. Restarted. Open Logic. Those demo dissapiered. I needed to do this one time more, because there was left demo just for Logic 6 Pro. Now I am lucky men again... :-)))