Insufficient Graphic memory

We have upgraded our 5060 thin clients.  Everything works as expected except when a user pull his CAC card and comes back to logon they get "Insufficient Graphic memory to create new session".  If they reboot the thin client they are then able to log back into to continue their Horizon session.  Has anyone else come across this odd behavior?  It is like the client isn't releasing the graphic memory when the CAC card is pulled?

Charles