my DC works a lot with my copies

[bertelo]

when I copy games from other cd's, or from internet images, they work (not all the time), but my DC reads thecd all the time, makes noise, and the games take a long time to load whereas the original cd's work great

My burning characteristics are
-liteon 24/10/40 5s59
- 8X writing speed
-discjuggler 3.5779
- mode 1 cdrom XA TOC 2352 offset 0
- Cd's: verbatims (blue)

can you help me?