[ubuntu] Vbox Guest Custom kernel boots, but cursor and keyboard frozen

Running 12.04.3 as host and 12.04.3 as guest. Compiled a 3.2.0 ubuntu-precise custom kernel on guest to patch a DVB media driver. Patched, compiled, installed without complaint. It boots and I can logon, but at that point the desktop appears with a cursor frozen in the middle of the pane, while the host cursor is free to mover around outside the pane. Capturing and uncapturing doesn't help. The keyboard doesn't work on the guest system either. Booting back into the original 3.8 guest kernel everything works as it should.

I'm using Vbox 4.3.6. on an HP 15-N028US laptop. AMD A-6, Radeon HD 8400.

Any help would be much appreciated.

Chris