after a period of testing with ZCM 10.2.2 we have rolled out the agent to approx. 80 clients. On all 80 clients we had to remove the old ZEN 6.5 agent and install the new ZCM agent... no problems so far.

After updating the agent (and assigning the workstations to the correct groups/bundles) we have seen the following problem at some random workstations:

After logging in you cannot right-click the 'Z-icon' to do a refresh or view any information...it simply does not work. After 2 minutes the icon disappears from the systray.
Another strange thing: we have seen this issue on random machines and the machines can be different every day...

I have checked policy's and tested with restarting services... but no solution.
Has someone seen this issue before?
Thanks for your help.