ASUS M6000: dual head & upgrade to fedora 8

[dhhb2304]

Since my message earlier was sent in HTML-format, I repeat it here as 
text: (sorry for the inconvenience)

I have an Asus M6000 laptop that gives me two problems:
*1. *when attaching a separate monitor to the VGA-slot on the back, I 
get a copy of the picture I see on the laptop screen (as it should!). 
Then, as root I enter into monitor management (sorry, my F7 is in Dutch, 
so the correct term is probably different in English) and activate dual 
head, giving the screen size and resolution of the external monitor. 
after OK, I get the order to restart X for the change to take effect. 
After having done this by logging out and again logging in, the laptop 
screen remains black and only the external monitor shows a picture. 
After restarting the laptop without the external monitor all is back as 
it used to be.
The video card in this laptop is a ATI Technologies RV350 [Mobility 
Radeon 9600 M10]
Has anybody an idea how to use the external monitor in order to enable 
an extended desktop?
I have tried to see whether I could change /etc/X/xorg.conf but did not 
find a way to do this.
I hoped fedora 8 would solve this problem, but see below:

2. I have downloaded fedora 8, burned this on a disk and used the disk 
to install on a desktop. No problem. I took the same disk to my Asus 
(dual boot with Windows XP) and started up from the disk and chose the 
option "upgrade an existing system". the system began collecting 
installed packages end thereafter checking dependencies. about 40% 
through this the system hangs completely (no mouse action either) and 
only using the on/off button  of the laptop gives any result.

B.