Yea, I can't understand much of what your saying. More information could also be helpful. What type of drive? What type of modchip? The media your using?
What's confusing is what happens when you insert a original disk. If properly installed you shouldn't get a dirty disc error.
Please help us so that we can help you.

all my games was burned on Verbatim DVD+R (DL 8.5) on speed-2.4X (with imageburn).
The main problem is with the backups , when I want to play with the backup disc I need to insert him to the xbox 360 immediately eject him and insert the tray again (most in case I do this action 2 times until the game shows up).
now the second problem that come just a few days ago is when im insert original disc after 1 hour of gaming the xbox tells me (messege) that i need to clean the disc and insert him again.
please guys give me solution for this.