Guest parameters are standard one
RAM 384Mo on 1Go, ACPI, 1 cpu AMD 1.8Ghz with PAE/NX,
Video Ram 64Mo on 512Mo with 3D acceleration,
PIIX4 and SATA (AHCI), CDROM
DirectSound ICH AC97
PCnet-FAST III (Am79C973) NAT
USB 2.0 EHCI
It works fine until I install the additions following chapter 4.3 of VirtualBox documentation. At restart, Ubuntu is slow, choice on menu are not always in rollover mode (the color is not brown, but if I click on it, the choice is correct - specially on the last option - like shutdown), in terminal mode, delay between action and display is 1/2-1sec. I got about 256Mo of free physical memory in windows while the machine is running, cpu used by the machine is between 30%-45%, GPU usage = 0%-2%.
As I only start the ubuntu machine, install additions and restart, this is the only thing that cause the problem, I guess.
As I'm novice on Ubuntu, may be is it possible to uninstall this additions or some part in order to check.
Notice, that's not very important, I may reinstall Ubuntu, but I think it could be useful to know what's the problem and how to correct/avoid it.
What do you mean with remote shell ? RDP server is not active.