Do you have an internal zip? An internal zip without a disk is like a hard drive without a platter assembly, when you start up knoppix it is trying to figure out how to use the IDE device it sees and searches for media and/or partitions. External zips are dealt with differently they require the loading of a module for support, they must be assumed to be removable media (like floppies and cd-roms), so the kernel can deal with the drive without a media present.

Also running knoppix on most systems with an empty IDE zip is no problem, on a couple of machines knoppix sat there for a long time trying to figure out what was up with the errors from the zip drive not having a media present to the point that on one machine I un-plugged the zip drive to run knoppix.

HTH

rock