Hmmmm,

From what I know, the black screen is probably where the XServer is trying to take "control" of the system / monitor / video card -=- Having an old Gateway, I could never get past the "black screen", or worse, would get the "Out of Sync" message pop-up on my monitor -=- in either case - the system was actually booted - I found this out by, waiting till all activity ceased on the CD-ROM drive, and pressing CTRL + ALT + F1 - and I was "transported" to text "login" screen, with all the boot messages on it...

You might try the following boot: cheatcodes: ( this one worked for my old system )

boot: knoppix screen=1024x768 vrefresh=60 noscsi

for the experimental kernel, use this replacement:

boot: linux26 screen=1024x768 vrefresh=60 noscsi

Usually, when you get the "black" screen, or the "Out of Sync" message, and no boot, it is probably a problem where Knoppix has detected what video card you have, and what its capabilities are, and is trying to use the "optimal" for it - but the monitor can't handle it ( the Out of Sync message - which is resolved with the "vrefresh" cheatcode ), or, the video card / monitor can't handle the resolution that it "thinks" it can handle ( just the black screen - which is resolved with the "screen" cheatcode )

You can press the F2 on the boot: prompt to see other cheatcodes, fbuffer, I think is another usefull cheatcode, never used it though, the above cheatcodes always worked for me...

Hope this helps,
Ms. Cuddles