If they're Audio CDs as opposed to MP3 CDs then try Burrrn (www.burrrn.net). I'd always use this in preference to Nero , especially V7.
It's free & worth a try.
For some burning at 16x (or thereabouts) works.
The CD-R that rapid_fire recommends are the best I'd recommend (I've several hundred of the Verb Pastels) but the Verabtim Super AZO are just about as good & perhaps easier to find.