Wyse P20 failes

The Wyse P20 authenticates towards the view 5.0 connection server, but then goes black or maybe there is just to few frames that is produced that it cant build a real picture because eventually I can see a frame of the screensaver.

When I look on the wyse p20 log it has several errors:
TRANSPORT :ERROR: transport_salsa_decrypt_from_desc_in_place() failed authentication
TRANSPORT :ERROR: Failed to decrypt packet in place
TRANSPORT :Could not decrypt packet!
TRANSPORT :Packet failed soft decryption

I get several of these by the minute. Ive tried both the encryption methods in the MC without any luck. I tried the software client from vmware and it worked like a dream but not with the wyse units...