Anytime the latency between the VM and the client goes over 20ms when using the signature pads you get random input instead of the actual signature. I have tested this in View 5 as well. Our MPLS averages 18ms so its very common to cause problems at the moment. I do have QoS in plase for port 4172.
Tested on vSphere 4.1 ESX/View 4.6, and vSphere 4.1/View 5
Any ideas much appreciated. Very noticeable problem to our users.