For example, Printer1 on print-svr or Printer1 on PRINT-SVR.
This didn't cause any issues with direct printing, however it did cause errors with some custom VBA print macros we use in Word 2010, particularly when setting the Active Printer. Turns out it is very fussy when it comes to case - the printer name and server need to match exactly to what is set in the VBA
Our VBA declares the print server names in uppercase. We deploy our printers using Group Policy Preferences, which maps using uppercase - so it should match...
Deleting and readding the printer did not resolve this issue, nor did deleting HKCU/Printers from the registry. Eventually, I found a fix...
For each RDS Server that had printers mapped with the print server name incorrectly as lowercase, I had to delete the following key from the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Print\Providers\Client Side Rendering Print
Note: As always with making changes to the registry, I would export the settings first incase you need to roll back.
This key is where all printer information is cached. If the printer was added to that RDS Server for the first time as, for example \\print-svr\Printer1, then subsequent connections would also be mapped in lowercase as 'Printer1 on print-svr.
After deleting the above key, I needed to restart the print spooler on the RDS Server. Finally, I readded the printer in the correct case \\PRINT-SVR\Printer1 which resolved this issue for me, and other users on that RDS Server.