Honestly, I think you're SOL.
Most CDRW/DVDROM combo drives can't read burned DVDs at all or can't read one type or the other (either +R or -R).
I attempted to find some hard data on your model of drive, but wasn't able to find any.
I suggest perusing the optical drive review sites, as they have the best information. Just because I couldn't find it doesn't mean it's not there.