That is certainly an oddity, and I have no idea on the cause, if it actually matters, call Xerox and escalate it to 2nd level support with the stuff I listed above. It may be a Xerox issue, it might be an MS one, it may be easily replicated too (people don't constantly create users on PC's so it may have just never come up, but domain users never seem to have this issue in those environments and that is common)
Here is how it happens.
1. I install a fresh installation of Windows 7, create a generic user account, and then install all the software and drivers. The fax works fine.
2. I add a new user to the computer using the name of the designated employee and log in with the new account, now the fax doesn't work anymore. Printing works fine though, it's just the fax that doesn't work.
3. I log out of the employees user account and log back in with the generic user account, and I can fax again.
So, are you saying if you (Dan) log into a PC and install the driver it will work fine, but if your co-worker (Let's call him Gary) comes over to that PC and you create him a new account and he logs in with his account it will do the messed up thing, then he logs out and (Sandra) who was already a user on that PC, then comes over she can log in and it will work fine?
That is odd, and it would imply a rights issue, but a rights issue should not be modifying output, it would seem more likely that the OS is swapping drivers (Windows 10 will often give new users the MS Class driver instead)
IN either case, you might be better off calling Xerox and supplying "Print to file" submissions to them so they can consult the code that is output to see what is being changed to help you troubleshoot why it happens.
Weird problem here. I install the driver and everthing works fine, but when I add an additional user to windows the lan fax stops working correctly. The output (what other's receive) looks blurry. I've tried everything I can think of to figure out what is causing the problem, but not lock. If you log in to Windows 7 with the original use account it still works ok, but if you use any of the other user accounts the transmitted fax looks like gibberish. The confirmation page also prints with a gibberish version of the page image. I've attached images of what the confirmation looks like. i've confirmed that the recipients also receive the blurry version. The first image is a confirmation from a fax sent from the original user account. The second image is a fax confirmation sent from the second user account.