Yes, you have the North American version, since it has an ESRB rating of T (for teen). The UK version has a PEGI rating of 12+, while the Australian rating is MA15+. I think the main difference between the English versions is the publisher's choice of copy protection and packaging. In any case, that should not cause any problems.
What exactly is your problem with the copy protection?
Make sure you have disk 2 (the play CD) in an optical drive, and not disk 1. If possible, try a different optical drive (the copy protection can decide it will only accept the CD in a certain drive).
Are you shutting down all non-essential programs (especially anti-virus) before trying to start the game?
You could try updating the copy protection drivers; Updating or removing StarForce drivers
If all else fails, if you get an error message (either 'disk detection' or 'no disk found'), click the 'Information' button, then when that finishes, click the 'View Report' button. Save the resulting text file somewhere, optionally zip it, and email it to Larian (email@example.com) with a description of the problem. They can create a file the copy protection can use to check your system on startup, rather then the play CD.
We should probably move this to a new topic, if it is going to take much more to resolve.