launch "startx" and the screan become black!

[hadilq]

hey everyone
I have Ubuntu 13.04 as host and ubuntu-server 12.04 as guest. I installed xorg and lxde because I need to run TileMill in server. Until this level startx works great. After that I tried to install VBoxGuestAdditions and relaunch startx and only a black screan appeared!! Trying to reinstall VBoxGuestAdditions did not make anything better. Any suggestion will be appreciated.
/var/log/Xorg.0.log is attached.
As a curiosity, why Vbox trying to install "VirtualBox USB Tablet" in guest??!!!!!

[Perryg]

The USB tablet is because you have the absolute pointing device enabled in the guest settings.
What version of VirtualBox guest additions and does the host use an nVidia graphics adapter?

Post the guests log file (as an attachment)

PS If you are needing the GUI why not just install the desktop version (which is basically what you have just made of the server)

[hadilq]

Sorry for geting late!
my VirtualBox's version is 4.2.10 and guest additions is the same.

Where can I found guest log? Would you specify the file address?

BTW, I dont want to mess my host packages + I need mapnik in guest server to rendering maps and TileMill is needed mapnik too! So I decided to install TileMill in server!! Acctually, I installed TileMill before with the exact configuration! But in this time I have no idea what is going wrong!

[mpack]

Where can I found guest log? Would you specify the file address?

Right click the guest in the VirtualBox main manager and select show log. Then choose save. Attach it here as a .zip or similar.

[hadilq]

Thanks for help.
The log files are attached.

[mpack]

00:00:00.596416 Host RAM: 2007MB total, 357MB available
...
00:00:00.703625 RamSize <integer> = 0x0000000019000000 (419 430 400, 400 MB)
...
00:00:00.704290 VRamSize <integer> = 0x0000000000c00000 (12 582 912, 12 MB)

You don't have enough unused RAM available on your host to run that VM.

[hadilq]

That is obvious I can not afford plenty of RAM, But I can launch WinXp in other VM and, as I said before, I ran starx successfully before installing TileMill in this VM.
I am so appresiated for your help, but still, I think there is another problem

[Perryg]

If everything was working until you installed a package in the guest then the issue is more than likely *NOT* VirtualBox.
Checking the requirements of Tilemill
http://www.mapbox.com/tilemill/docs/linux-install/

You are going to need more memory.