One out of five Citrix XenApp 6.5 servers is not allow clients to redirect/map their local COM4 to the Server COM1. We use a Net Use command at login to map a USB-to-serial signature pad that lives on client COM4.
The other 4 Citrix XenApp servers are properly redirecting/mapping the COM ports fine.
I checked the RDM Session Host Config. console and the ICA and RDP allow COM redirection...
Server: Windows 2008 R2
Citrix: XenApp 6.5
Client: XenApp Hosted Full 12.3