I'm writing this post from the BT5 Live CD. However, after install and reaching a CLI (on the HDD), when I run startx, my monitor simply displays 'invalid format' (obviously this works fine via the LiveCD)... I've installed Ubuntu and Fedora a few times on a few machines, and have never had any issues with the display... not sure where to start troubleshooting. Any help is appreciated.
*note* I am running an Asus P5L-MX mobo, it uses an Intel onboard display.

What happens if you run the following command?

root@bt:~# exec gnome-session &
[1] 1205
root@bt:~#
** (gnome-session:1205): WARNING **: Cannot open display:
(I hit enter here as the cursor sat there for some time)
[1]+ Exit 1 exec gnome-session
root@bt:~#

Here's some warning I have in my Xorg.0.log (I dont have any errors, only informational, defaults, or warnings)
(==) Automatically enabling devices
(WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
Entry deleted from font path.
(WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist.
Entry deleted from font path.
(WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist.
Entry deleted from font path.
(WW) The directory "/usr/share/fonts/X11/100dpi" does not exist.
Entry deleted from font path.
(WW) The directory "/usr/share/fonts/X11/75dpi" does not exist.
Entry deleted from font path.
.........
(--) PCI:*(0:0:2:0) 8086:2772:1043:817a Intel Corporation 82945G/GZ Integrated Graphics Controller rev 2, Mem @ 0xdfd00000/524288, 0xe0000000/268435456, 0xdfd80000/262144, I/O @ 0x00008800/8
(WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory)
(II) LoadModule: "extmod"
.........
(II) intel: Driver for Intel Integrated Graphics Chipsets: i810,
i810-dc100, i810e, i815, i830M, 845G, 852GM/855GM, 865G, 915G,
E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM, Pineview G,
965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, Q35, Q33, GM45,
4 Series, G45/G43, Q45/Q43, G41, B43, Clarkdale, Arrandale
(II) VESA: driver for VESA chipsets: vesa
(II) FBDEV: driver for framebuffer: fbdev
(II) Primary Device is: PCI 00@00:02:0
(WW) Falling back to old probe method for vesa
(WW) Falling back to old probe method for fbdev
(II) Loading sub module "fbdevhw"
(II) LoadModule: "fbdevhw"

Also, some output from my VGA in lspci:

root@root:~# lspci -s 00:02.0 -v
00:02.0 VGA compatible controller: Intel Corporation 82945G/GZ Integrated Graphics Controller (rev 02)
Subsystem: ASUSTeK Computer Inc. Device 817a
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at dfd00000 (32-bit, non-prefetchable) [size=512K]
I/O ports at 8800 [size=8]
Memory at e0000000 (32-bit, prefetchable) [size=256M]
Memory at dfd80000 (32-bit, non-prefetchable) [size=256K]
Capabilities: [90] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable-
Capabilities: [d0] Power Management version 2
Kernel driver in use: i915
Kernel modules: intelfb, i915