hi - sorry for joining the thread late - I hope i can help;
when the problem presents;
- can you see the device in the View Client Menu?
- does USB redirection of other devices work (eg a usb storage device)?
if you can't see the device in the menu, then it could be that it is being blocked. Smartcard type devices are blocked by default.
Normally, smartcard type devices are better redirected using smartcard redirection. For this to work you need to install the smartcard option on the Guest VM during the View Agent install process. And, you must be using PCoIP.
However, if you don't want to use this feature (or it doesnt work for your specific device) and you need to use USB redirection, then you may need to enable the use of smartcard devices via USB.
On the agent vm (or AD etc) launch the GPO editor, and make sure that smartcards are set to "enabled".
close the client, and re-launch. From then, the device should present in the menu available for forwarding.
Let me know if this works. If not, then I may need to see some extracts from the client logs to help see whats happening,
cheers
peterB