both drives as CD drives only - do you mean in 'My computer'?
If so, join the club. All of my machines run WinXP and on all of them the drives are recognised this way - because as far as Windows is concerned that's what they are. They work perfectly well, as you say, so it doesn't make any difference.
If you look in device manager in Control panel/system/hardware you should see the drives identified specifically under the DVD/CD-ROM drives heading.