I also had problems with my Lexmark. The icon while printing showed a different printer in the Dock. I got excellent service from Lexmark and their reply is below.
It seems that it's important to disconnect the USB from the printer and come off the Internet after downloading.
Ignore the .exe and Winzip stuff.
By following their instructions below, I have the X9350 printer icon in the Dock:-
Delete the Lexmark folder found in /Library/Printers (that is, remove the
contents as well as the folder itself).
Delete the file LexmarkUSBMerge.kext in /System/Library/Extensions. Once it
is removed, restart your computer.
1. Please copy and paste the link given below in the web browser.
http://www.downloaddelivery.com/downloads/cpd/9300Series_Web_InstallerLPD.dmg
2. Save it onto Desktop.
3. Once the file has been downloaded, log off the Internet and close all
programs.
4. Double-click the downloaded file to open the Winzip Self-Extractor
screen. The WinZip program will offer a folder to unzip the files to.
5. If you want to use this folder, click Unzip. If you want to use another
folder, use the Browse option to locate it and then click Unzip. The files
should then begin unzipping into the folder.
6. Once the files are unzipped, open the folder and look for the setup.exe
file.
7. Double-click on this file. The driver installation will start. You will
first see a Lexmark License Agreement.
8. Read the information and select Yes if you agree to the terms. (Note: If
you select No, you will not be able to install the printer driver.)
9. Follow the on-screen instructions to complete the installation.
During installation please select as wireless, and let the usb cable be
unplugged and when it prompts to plug the usb cable only then plug in the
cable.