Here are some further details:
We have the issue in both our live and test environment. The version of View in live is 5.1 and in test it is 5.2.
We do not tunnel the connection.
The issue happens from thick clients with the View client, thin clients Wyse D50 and zero clients P25.
The VDI’s are W7 connecting via PCOIP over the LAN.
DNS is configured and working fine.