HP LaserJet 5L and Cups

Hello,

I'm getting some trouble with having my HD-installed Knoppix 3.4 getting my printer to work. It's properly detected and configured by Cups (and my test pages are quite fine), but when I print some pages from an application (e.g. Openoffice or gv) it happens that "the top half of the page was very pixelated and the bottom was cut off", just as exposed here.
What's weird is, when I had Knoppix 3.3 installed, this didn't happen (as my 5L worked fine with previous Linux installation such as Redhat 9 and before).

I searched the Web seeking for a fix, but I found only:

• use LaserJet 4 drivers instead of 5L ones -> no good :(
• remove and reinstall Cups -> removing Cups would remove lots of packages (when I dared do this, I had to reinstall all after :? )

Has anybody some better solution than changing my old but working HP 5L?

TnX