If you find that your Citrix sessions are not logging off gracefully, you may find this as a result of lingering background processes. Analyse these sessions using the Citrix Management Console (CMC) and identify the problematic processes. For example, we experienced this issue after installing new HP printers into our environment. The following processes were causing us grief and preventing users from logging off gracefully:

• hpmup081.bin
• hpmup083.bin

To resolve this issue, we added these processes to the "LogoffCheckSysModules" registry key located:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Citrix\wfshell\TWI