I dont see why Lexmark software could be the cause,however have you tried uninstalling the Lexmark software and run ccleaner click here and reboot,then try your cd/dvd drive again.
Couple of things to try;
Uninstall the drive in Device Manager and reboot,let windows find and install the drive again.
Check the drive is set to DMA and not PIO,reset tool click here
Reset the drive with this tool from Doug Knox click here
Finally look for and remove any upper and lower filters,
Then follow these directions for clearing the Upper/Lower Filters: (might want to print this out)
1. Click on Start --> Run --> and type in 'regedit' followed by the enter key ( if Vista Start search or windows+R )
2. Expand the "HKEY_LOCAL_MACHINE" key (looks like a folder) by double clicking it (or
3. clicking the "+" next to it.)
4. Expand the "SYSTEM" Key
5. Expand the "CurrentControlSet" Key
6. Expand the "Control" Key
7. Expand the "Class" Key
8. Please look for a key containing the following string of letter and numbers:
9. High light this key by left clicking once on it
10. On the right hand side you are looking for "UpperFilters" and "LowerFilters" under the "Name" column, once you find these please delete them by right clicking on them and choosing "delete"
11. Please exit the registry by clicking on the "X" in the top right hand corner of the screen
Reboot your computer
A few things to try out,if no joy post back.