Back in 2002 whether there are some dreamcasts that CAN'T play copied games had been a subject of controversy in the dreamcast community . There was a lot of people that claimed all dreamcasts can play any cd-rom you can throw at them and another lot of people claiming that they were sure they have seen dreamcasts that have some mysterious copy-lock.
To my recollection, the debate lasted a while, but no conclusive proof was ever presented that in fact there are DCs that are copy-locked. :-?
So chances are that if they do exist they are extremely rare. I have owned three of them (bought in two different countries) and all of them have been able to boot off and play normal CD-Rs.
-With regards to the sega web browser - let's say it was never the best, it just got the job done.
Recently, a bunch of nice people came up with a homebrew internet solution for the dreamcast, incl. browser, irc client and maybe more (I never got the time to try it).
It is called "psilocybindreams" and you can donwload an iso of it from
http://www.psilocybindreams.com/ (totally legal)
You can find other interesting freeware games, emulators (ScummVM, SNES, Genesis, GBA etc) in the following websites:
http://www.dcemulation.com/http://www.dreamcast-scene.com/ For some weird reason (probably to do with overcoming GD-rom sensitivities) you'll have to use a pc cd-burning software called "Diskjuggler"
Oh and a bit of advice, burn all your CDs at low speeds (x2-x8). Dreamcasts can be picky with data-error prone CD-Rs (which is what happens when you burn a CD at a speed say >x24)
I'm no big fan of DC but my 5 y.o. brother really appreciates it. :lol:
I hope this helps!