Fov, the white version is the USA version. I don't think it uses the same kind of copy protection as the UK version.
If you look at the undersides of the CD's from the UK version (at least this is true of my UK version) you may notice two concentric circles on CD1 where it appears there is no data written. You don't see them on the other UK CD's and I don't see them on any of the CD's of my USA version. When I used the checker.exe utility to check for bad sectors on the CD's, it reported two bad sectors on CD1.
I remember reading about these circles in the adventure newsgroup around the time the game came out. I forget who identified them as a form of copy protection. A search at Googlegroups found this http://makeashorterlink.com/?U2E024A45
The messages from Scott Butler and Tragedy Trousers are of the greatest interest. I can't say for sure if this is the thread where I read about it, but the information is similar.