Just a thought: I recently got a copy of Project Gotham Racing on the Classics range (2 for £30 at Game). I played it without my chip on in a normal profile. I got a few read errors with the disc so I turned the chip on and created a new cheating profile so I could play Cone Attack (sometimes I get less errors with the chip on, go figure).
Today, with the chip off, PGR won't let me play the cheat profile with my chip off - it says TV Mode 60Hz. I run a PAL machine with the PAL video mode on, apparently in 50Hz (I forgot when I reset my eeprom I had to change the videomode back). Anyway, the point is PGR locked me out of the game because it thought I was using a foreign game save.
2 points for the conspiracy theorists:
1. Have the Classics been modified for this to happen?
2. Would Live check game saves for
any game to check they've been hacked, even non-Live games...?
Hmmmmm..........