DC - only burned games will play

[call_me_sir]

So I just bought some DC games on ebay, it's almost Christmas and I wanted to relive the first time I played Shenmue, box and all. I have it burned and it works fine, but my originals - all but skies of arcadia - have gotten lost over the years. Now what I've discovered from tweaking the pot for the last hour is that no matter what, legit games will not play. They're scratch free and mint, but won't play.
WTF?
I always thought playing burned games was harder on the laser, but if so why do they play without a hitch?

[Elite Evil]

Is there a region lock on dreamcast? Can you boot them with utopia or anything? Can you get on it with action replay or xploder or something?

[call_me_sir]

Probably not applicable, since Skies of arcadia (retail game) doesn't boot either and it always used to. It's like reverse laser damage! I always thought that when the laser started to go from cdr reading (if I remember correctly it reads cdr's at half the speed of GDR's, and damage is done over time from trying to compensate), it would only read gd roms, so this is weird.

When I try to play the legit games I get as far as the sega copyright screen, then right back to the dc menu.

[Elite Evil]

Try and boot them from a boot disc, might be another regions BIOS or something?