Bug: VirtualBox 4.3.18 and VT-x incapable architecture

Symptom: Your VirtualBox VM is crashing randomly after some hours of work with a Guru Meditation alert box. The VM was stable until 4.3.16. The VBox.log shows incidents like this: 04:10:00.862330 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 04:10:00.862334 !! 04:10:00.862335 !! Guru Meditation -2403 (VERR_TRPM_DONT_PANIC) 04:10:00.862364 !! 04:10:00.862415 !! TRAP=0e ERRCD=0000000000000000 CR2=00000000a004ed08 EIP=8b4b3156 Type=0 cbInstr=ff 04:10:00.862466 !! EIP in VBoxDDGC.gc …