I am running debian wheezy.
I downloaded, and extracted the Lexmark driver.

tar -xvzf lexmark-inkjet-legacy-1.0-1.amd64.deb.sh_Pro900.tar.gz
lexmark-inkjet-legacy-1.0-1.amd64.deb.sh

edhe@hebrews:~/Downloads$ ./lexmark-inkjet-legacy-1.0-1.amd64.deb.sh
Verifying archive integrity... All good.
Uncompressing nixstaller.......................................................................................... .....
Collecting info for this system...
Operating system: linux
CPU Arch: x86_64
TRACKING IDENT = 140509
cpu speed = 1000 MHz
ram size = 1947.60546875 MB
/tmp = 8742 MB , /usr/local = 3501 MB

After the LEXMARK Linux installer opened, and I entered the root passsword, the Install would go no further that what you see above.

If you download a .deb package use gdebi it will resolve dependencies for you. All you have to do is right-click on downloaded file & select Open With>>Gdebi

edhe@hebrews:~/Downloads$ man gdebi
edhe@hebrews:~/Downloads$ gdebi lexmark-inkjet-legacy-1.0-1.amd64.deb.sh
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done
Unknown package type 'lexmark-inkjet-legacy-1.0-1.amd64.deb.sh', exiting

edhe@hebrews:~/Downloads$ ls -alh lexmark-inkjet-legacy-1.0-1.amd64.deb.sh
-rwxr-xr-x 1 edhe edhe 18M Dec 16 2010 lexmark-inkjet-legacy-1.0-1.amd64.deb.sh

All you have to do is right-click on downloaded file & select Open with>>Gdebib, you don't need to extract it from it's folder

I tried the right click on the file in my File Manager (Dolphin) and nothing seemed to happen.

So I tried, in an xterm,

gdebi lexmark-inkjet-legacy-wJRE-1.0-1.amd64.deb.sh_Pro900.tar.gz
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done
Unknown package type 'lexmark-inkjet-legacy-wJRE-1.0-1.amd64.deb.sh_Pro900.tar.gz', exiting

Try this download. it's just a .deb
http://support.lexmark.com/index?pag...mentLINUX_UNIX
Alsop if you don't have gdebi then install it also.

That only supports Debian 6.0. Wheezy is Debian 7.0