VM powers off and can't be resumed when I close laptop lid/suspend

[fpn]

Came back to the office, connected my Mac Book Pro, opened the lid and the VM I use for work every day was gone.

No crash report in the OSX diagnostics log.

Two wonky things happened: a) the Mac didn't suspend when I closed the lid (it normally does and Virtualbox is the only thing running on it) b) Virtualbox suspended the VM, but when I started this morning it wasn't able to resume

This seemed to work fine before (4.3.0-89960).

I upgraded yesterday to 4.3.4-91027

Host: OSX - 10.8.5 Mac Book Pro

Guest: Ubuntu 12.10 Guest Additions - 4.3.4-91027