4.0beta2 History disappeared

After upgrading to 4.0 beta2 from 3.5 all my history (like ping) disappeared.
Does anyone have any ideas.

lol.
Just rebooted the server and everything came up…
Problem solved.

A few hours later…

The problem is back. Rebooting the server did not solve the issue.
History is blank - no ping or other service report…

Can any body help?