[BigDaddy]

OK, I didn't notice Johan's post (I was wondering what method was used). Pre-generated number tables are very common (they are more efficient), but I think an artifact could still cause problems.

I don't think the seeding technique is likely to be the problem. I believe the seeds are used to select a starting point on the table and a "movement" pattern around the table, and it can be made even more comples. Repeats are highly unlikely in any case.