V50le connect only 1 Time to server 2008 R2

V50le connect only 1 Time to server 2008 R2

WE Buyed two v50le with Linux V6 and want to connect to our server 2008 R2.
WE have much v10l they works nice!

But the v50le connect and when i want to Connect a second Time it is Not possible...
The rdp window Closes fast.

Checked the nt4 Option. But no help.
Ntlm is deaktiv on server...
And also old Versions of rdp are allowed.

The Client gives a internal licence error?!