I had the same problem for a Z65 model. It seems Lexmark don't want to support Linux drivers anymore
I'd suggest using google to search for the driver file from an archive site.
eg. http://ftp.nluug.nl/pub/os/Linux/dis...srepo/sources/ looks
to have the Z35 driver file: CJLZ35LE-CUPS-1.0-1.TAR.gz
Download this file and follow the instructions on this forum changing
the file name references to your driver filenames.
I did this with a Z65 driver file: CJLZ65LE-CUPS-1.0-1.TAR.GZ
and finally got a successful test page. Using this HOWTO I got it
working in about 15 mins!
The key for my system (KUbuntu 8.10) was the /etc/fstab file update,
plus needed to install v5 of libstdc++:
sudo aptitude install libstdc++5
Unfortunately I didn't find this HOWTO first and was trying an
install method from an older forum topic specifically for Z65 which didn't work which wasted a few hours beforehand.