Need help burning a "backup"

[Shead]

I'm using a hp 9100 and generic 700MB CDs. I think the problem might be the CDs, but I want to be sure before I try them on more expensive CDs... Can I burn them on 650MB cds? Because I have a couple of Verbatins here, but I dunno if 650MB is enough.

Oh yeah, I forgot to mention... The generics I'm using worked when making the Boot Disk and the VCD player, a couple of days ago, if that makes any difference...