Oracle VM VirtualBox Manager reports an error

[Erich]

While defraging within the VM using MyDefrag, the VM stops working and the host reports a generic error message, "Oracle VM VirtualBox Manager reports an error and must be closed." (Loose translation of the German error message.)The VM is displayed in the VBox GUI as having been aborted. This doesn't happen all the time, just every now and then. Host and Guest are both XP SP3 with all MS updates installed. This also happens with a second Guest. If I restart the VM it will boot without issues and I can rerun the defragmentation without issues. Two errors are prominent:

ERROR [COM]: aRC=VBOX_E_IPRT_ERROR (0x80bb0005) aIID={09eed313-cd56-4d06-bd56-fac0f716b5dd} aComponent={Display} aText={Could not take a screenshot (VERR_NO_MEMORY)}, preserve=false

and

ERROR [COM]: aRC=VBOX_E_IPRT_ERROR (0x80bb0005) aIID={05044a52-7811-4f00-ae3a-0ab7ff707b10} aComponent={Mouse} aText={Could not send the mouse event to the virtual mouse (VERR_PDM_NO_QUEUE_ITEMS)}, preserve=false

[Erich]

Logfile