I just noticed that my MF4350D wasn't working today (oddly enough, because Excel started freaking out). Upgraded to Mountain Lion on release date.
I tried what PAHU recommended in other threads for removing old versions, etc., and I still cannot print.
In my case, the printer is connected to a Win 7 Ultimate machine in the other room. Up until Mountain Lion, I was able to print to it just /fine/. Now, I apparently cannot. At best, I get the -50 error. ANY suggestions?
EDIT: (more info)
When I try to print, I get a popup with the follwing:
The printed output may be incorrect because the printer information has not been acquired.
Start Printer Utility to get the printer information.
Then I get the -50 error. The printe utility populates the info just fine.