Comment 5 for bug 303475

I'm marking this as duplicate of bug 303199 - it is really a problem with virtualbox-ose-MODULES after all.

There are several workarounds: Use virtualbox from virtualbox.org (which has a Debian repository, too), install the modules manually (module-assistant, has been posted several times when this happened) or wait with the kernel upgrade until virtualbox-ose-modules has caught up (not recommended though!). For the last workaround, you can "just" boot the previous kernel from the Grub/bootloader menu (not recommened, since this kernel has known security issues).