I've had a few problems for a while - those little things that you keep working round because you are busy, but keep cropping up.
Finally got around to upgrading both Virtualbox and Vagrant to the latest version, and at least one of the problems still seems to be there so am wondering if anyone else has a problem.
1) The main problem is NFS - i'm using NFS for my /vagrant directory as the normal shared dir was so slow serving a rails app. However, every so often, the NFS share becomes unavailable and the VM just stalls looking for it. I have to vagrant halt and then vagrant up, and all is well again. I'm running OS X Mountain Lion with all the latest patches. Had other users with the same problem too, so it's not just my machine.
2) Vagrant often asks for the Administrator password when bringing machines up - even though no settings have been changed.
3) Every so often, the VM will not be able to resolve DNS. Had this with a few different users, so again it's not a machine specific thing. I think I may have fixed this one by using: