GB is WAY out of my field of expertise, but, it seems from some stuff I have read online, that GB *may* only do 16bit/44.kHz, which is the right sample rate and bit depth for CDs. If thats correct, it could still be your machine not being able to "keep up" (which is to say that the machine is trying to burn, but has to do too much in the way of things other than the actual burning itself..i.e. conversion of file formats, etc.), then one thing that may help would be to convert the songs to "final" file format first to make that part of the process a separate thing from the burning, then later, to burn those files to a CD as an audio CD.
This page seems to have a method to do that, it refers to it as the "Never Fail" method. (dunno if it will help tho)
http://www.thegaragedoor.com/tutorials/faq.html
If you have the option, burn your CDs at the slowest speed possible. Also, don't have any other programs open when you get ready to burn the CD.
That said, "medium error" does sound like something in the actual burning, most likley, the discs themselves, because the "Medium" they refer to is the disc itself.
So, with that in mind, the following things may either be things you already know, or (hopefully) they will be helpful. It wont hurt anyway.
CDs are written to by the computer on the *opposite* side that you would write on if you were labeling them with a sharpie.
Especially before burning, don't let anything touch that side of the CD, and don't place that side down on anything. On CDRs with writing on them from the factory ("branded" CDRs, as they are called, will often have the company name on there, for instance), the side without the writing is far more delicate than the side with the writing (from the factory) on it, and any impurities on that side can potentially muck up the burning process. A smudge that would not cause a skip on a CD that was already burned when it got the smudge could easily cause the CD to error out while trying to burn it.
Ideally, you would want to take the blank out of the package and put it directly in the computer when it is ready to be burned.
If that doesn't help, one thing you can possibly do as a work around is burn the WAV files you make (with the advice from the FAQ page linked above) onto a CDR as data files, as versus burning them as an audio CD, then take that CDR of data files to another computer, and copy the data files onto the 2nd computer, and burn them onto a CDR as an audio CD on the 2nd computer. It sounds worse than it is, actually. The reason that might help you is that burning a data CD employs all kinds of error correction that burning as an audio CD does not employ. That error correction could be enough to get you past the CDR drive and/or CDR Media and/or computer issue you are having now on your computer.
That is pretty much all I have, so if all that fails, it may be that your burner is the issue, or that you just haven't found the right blank CDR brand yet.
Good luck. Let us know how it goes if ya can.
G
