We have P25s, and after upgrading View Agent (only) from 5.1.0, to 5.1.2, our users with their second monitor in a vertical position (1600x1200 and 1200x1600) experience the issue, but users with both horizontal configurations (1600x1200 and 1600x1200) do not experience the issue. Upgrading the Teradici firmware from 4.0.2 to 4.0.3 does not fix the issue.
We are having to force everyone to use horizontal monitors.
From reading this thread, it is disappointing that VMWare has not been able to address this issue. Considering that purely a View Agent change from 5.1.0 to 5.1.2 causes the issue, it is clear that whatever is being sent via the PCOIP encoder in the View Agent is changed or broken in some fashion, so that the teradici chip is no longer able to decode it properly. It would be nice if someone in the VMWare staff would take up the issue and fix it. I would start by looking at the changes in the PCOIP encoding code between 5.1.0 and 5.1.2.