Couple more things regarding the PCoIP clients... How many monitors do the endpoints have? We noticed that if you have three monitors and rotate one of them to portrait while leaving the others at landscape, it will cause disconnections. On the default landscape setting, the zeros will operate normally with up to four monitors.
I also experienced disconnections issues on a particular version of firmware. Definitely use the management console mentioned in a previous post to get a look at the version in use.