I think there often some problems with OEM versions of software. It might be worth investing in a full version as if you change your writer it may not be recognised by this version of the software.
For burning audio CDs there are a number of excellent free apps. The one I often use is BURRRN (www.burrrn.net). It'll take in audio of various formats & convert to wav on burning for an Audio CD. Well worth a try.
I would recommend though that you change your media as those 4x CDs must be quite old now & could be deteriorating. I actually have had loads of problems with Memorex 24x which I dumped in the end. Poor quality media is often seen as a cause of many of the questions on this forum.
I would recommend Verbatim ( Pastels, Super AZO or Datalife Extra Protection - in that order). The Super AZO might be the easiest to find.
With quality media & a decent CD Writer you shouldn't really have to drop the burn speed down from the rated speed of the media. I burn all my CD's at 40x which is the max for my Liteon CD writer.
Edit: I just recalled that you're using CD-RW so some of what I've written may not be relevant to you. However, I've just finished watching the LOST series which I convert to VCD & burn to CD-RW to watch on the TV. In the end I gave up with the RW discs & burned to CD-R as I was getting so much break up of the video on the RW discs. RW to seem to deteriorate over time. Bout time I got some new ones, maybe you should also if you want to continue with -RW media.