Printers seem to be the biggest problem with Citrix XenApp servers. Here is a quick shot from Moshe Silber on Citrix’s Print Detective utility to help troubleshoot those issues.
Print Detective is an information-gathering utility that can be used for troubleshooting problems related to print drivers. It enumerates all drivers from the specified 32-bit Windows computer, including driver-specific information. It can also be used to delete specified print drivers. It also offers logging capabilities and provides a Command Line Interface (CLI).