Several have asked about properly configuring UPD for Xenapp 4.5, 5.0 and earlier versions of Citrix Presentation Server. Follow this documentation for optimal printing with the universal printer driver.

1. Open the Citrix Presentation Server Console... Start > Programs > Citrix > Management Consoles > Presentation Server Console
2. To create a policy hit "alt+P" or right click on Policies, and select Create Policy... once the CPS Console is open.
3. Now configure the following settings:
   1. Expand Printing
   2. Expand Client Printers
   3. Click on Auto-Creation
      1. Set to Enabled
      2. Set "when connecting to" -- Auto-create all client printers
   4. 
   5. Expand Drivers
   6. Click on Native printer driver auto-install. This will allow you to keep a clean server and not junk it up with a bunch of random printer drivers and driver inconsistencies across your farm.
      1. Set to Enabled
      2. Set to Do not automatically install drivers
   7. 
   8. Expand Drivers
   9. Click on Universal Driver
      1. Set to Enabled
      2. Set to Use universal driver only
   10.