Am trying to run Ubuntu-64bit as GuestOS on my Win7 laptop
The virtual box fails to start with a timeOut error. I've attached the error popup and Log for reference.
As a general rule I don't see how else you can benefit from bugfixes, short of the devs travelling back in time to fix the version you have.
As to whether the latest version would actually fix your problem: I don't know, but we would certainly be more interested in knowing about any issues that arise.
OTOH, if you want to stick to an older version you regard as stable then that's fine too, but bug reports for obsolete releases are really pointless: you have to demonstrate that it's something for the devs to concern themselves with now.