I've been plagued by the same problem for the last 6 weeks, ever since I upgraded to ZAISS 8.0.298.035.
I've also seen a marked increase in random reboots during the same period. The other thing I've noticed, while not especially harmful, is that the Junk E-mail & Anti-Fraud Filter no longer shows its progress through downloaded e-mails; instead, the box where the green bar appears remains blank while the Filter processes e-mails (meaning you can't tell if it's working or not).
I've scrubbed ZA off the computer several times and reinstalled it, all to no avail.
ZA Technical Support tells me they can't replicate the problem, so they've got no suggestions!
Today, I finally said enough and reinstalled ZAISS 8.0.059.000.
But I don't get any of the improved features.
Hopefully, the next version
will fix the problem.
I'll try it when it's released, but keep a copy of 8.0.059.000 handy in case it doesn't.