Did you try -t cdrom with your mount?
And there's another option -ioctl.

Of course I added the -t cdrom...
And in the readme is mentioned that -ioctl is only for win2000 and xp or something (definitely not for 98se). But I'll try that one too when I get home.

Well, I don't know, what you are actually doing, but you shouldn't mix usecd, aspi and ioctl, only use one of them.
Since you've tried -aspi, I assume you're using scsi-drives; perhaps you have to update your aspi-layer:
http://www.adaptec.com/worldwide/support/supp … odkey=ASPI-4.70

To see, if it's working at all, you should mount a cd with:
mount d g:\ -t cdrom
If you don't happen to see your files with dir then, there's something wrong with your system.

Ok, it works. The problem is that I have an azerty keyboard: I need AltGr to type "\". I typed "/" instead, and apparently it doesn't work all the time.
I discovered because I couldn't mount a directory from my hdd today, which was ok yesterday. The weird thing is, that if you try it on a dir, you get the message that the dir doesn't exist, while when using it on a drive (hdd or cdrom) you don' get an error message, but then the dirview is empty. So I just made a batchfile that mounts my cdrom using -c "mount d f:\ -t cdrom".