Hmm, I don't really see a bug, neither in Kernel 3.10 nor in Virtulbox 4.3.2. I mean, I haven't experienced any problem, even after last upgrade of Kernel and / or Virtualbox.
But, I'm using KDE 4.11 (64bit) with Kernel 3.11 (not 3.10) in combination with Virtualbox.4.2.18 before and now 4.3.2.
Maybe there is a problem with Kernel 3.10 in some combination with Virtualbox, but as I've said, I haven't experienced any problem.
Just an idea: Could you consider to install Kernel 3.11?
-Linuxfluesterer (I love KDE ...)
I really hope, that by the Brexit (poor Britain), TTIP will be finally prevented. But don't get tired to talk to your local politician to open eyes for danger to democracy because of TTIP