No autocreated Client Printers
Event Viewer showed no errors and the normal citrix autocreated client printer troubleshooting had been performed. (i.e I could manually map the printer all OK)
The problem turned out to be from a XenApp 4.0 build script that cleaned up the ICA Channel permissions. It removed all permissions then set them up again.
Xen App 4.5 has changed in that it no longer uses the CTX_SMAUser account for printer tasks and now uses the CTX_Cpsvcuser and local service account. The CTX_Cpsvcuser account needs to be added and assigned the following permissions
"Query Information"
"Virtual channels"