I cant seem to make a backup of gears of war, all of my other games backed up with no problem. But I cant seem to make one of my gears of war disk. Any suggestions? A million thanks in advance.

Itd help if you left a few more details than that.
I assume you are using wxripper considering you mentioned swap disc? If its a disc reading error (i dont think wxripper has any retries or anything on reads, so it might fail more than usual at this) you could try hotswapping with a different drive or something (i find my lite-on and asus drives read MUCH better than the pioneer, both faster and without as many errors on bad discs)
Or perhaps it needs a new layout file thingy (Im havent really looked into it much, so I cant remember what they do )
Its possible xdvdmulleter might read it too, depending on whats actually wrong, but if you try that ENSURE you use the clond dvd9 option, or it wont work. (not that mulleter is especially wonderful at this, but at least it retries on errors which should make it somewhat better than wxripper)

either way, without more details its hard to help
but i did my best