Hardware :: Disable Secondary Graphics Card On Xorg.conf?

I installed Ubuntu 10.04 on my sister's laptop (it's a Packard Bell; not sure about the model, but I could check); it has two graphics cards: the primary is an ATI Technologies Inc Mobility Radeon HD 3650, and the second one is an Intel Corporation Mobile 4 Series. After installation, installed the ATI driver through the restricted devices manager (xorg-driver-fglrx package, I think), and after a couple of reboots, the screen simply went black after boot and I couldn't do anything (I couldn't even switch to a virtual console, and booting on recovery mode was the same). So I booted with the ubuntu live flash drive from which I installed it, and deleted the xorg.conf file, and now I have a GUI, but it uses only the Intel card. I would like to use the ATI card if possible, but the problem is, if I use a xorg.conf file set up to use the fglrx driver, then I have a black screen, and if I use no xorg.conf file, it automatically switches to the Intel card. I also looked in the BIOS for an option to disable the Intel graphics card, but it doesn't have it (it's a very simple BIOS). So, since there seems to be a conflict between both cards, is there a way to tell xorg to ignore one graphics card? (the Intel one, in this case?).

P.S.: Here I attach two Xorg logs: Xorg.0.log is the last one (without using a xorg.conf file, and using the Intel card), and the Xorg.1.log file is the one of my previous attempts at using the ATI card.

I forgot, here is the outpput of lspci:

Code:
00:00.0 Host bridge: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub (rev 07)
00:01.0 PCI bridge: Intel Corporation Mobile 4 Series Chipset PCI Express Graphics Port (rev 07)
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:1a.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 03)

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