Pfsense hangs randomly

[juicejug]

I'm having a problem where this 2.3-RELEASE will randomly just hang or freeze.

This has happened on 2 different installs, both as hyper v guest virtual machines. On one vm, I changed the setting kern.ipc.nmbclusters="1000000".  This vm hasn't froze since. Assuming that was the problem, I changed the other vm to the same.

This vm has now been better (up for longer periods of time), but still randomly hangs. Most recently it was up for 18 days when it hung. It previously would hang every couple of days.

The graphs don't indicate any spikes prior to a hang but look like regular operation.

Is there anything else I can tune or look at to fix this?