Ati mobility radeon 9200 works only on external monitor

hello!

could someone help me with this?
first of all, yes i have read many posts on similar topics and all of them ring a bell but none fits my problem. or then, i haven't found that one. so idecided to start a new thread...

the story so far:

i got this compaq presario x1000 laptop for free because the monitor is not working. actually it would display everything but without the blacklight so after a while i diagnosed that the inverter is not working anymore.

so now i am using an external monitor lg flatron 575lm, res. 1024x768. (i think the laptop itself has 1280x800).

graphic card ati mobility radeon 9200 (although everst says 9000), driver for the radeon 9600 series, have also tried radeon 9000 series, both work nicely on the external monitor)

everything was peaceful, until yesterday when i was playing with a program called smac (spoofing my comps mac address), had to reboot, and both monitors are working! but only until windows starts loading drivers, then it's again only the external monitor. though it seems that the backlight is active now, but the screen is black. immediately i tried to get the monitor working by installing and uninstalling drivers, wiping all ati drivers away with driver cleaner, try again... for many hours...

the result is always the same:
the laptop's monitor works nicely with vga (and the external too), but goes black when i install the ati driver. then the external monitor works nicely, all 3d accelerations and clear sharp picture and everything. and in windows display settings it ALWAYS recognizes the external monitor as the first, and the internal as the second and ALWAYS the internal is grayed out, inactive, can't change it to primary, can't expand the desktop onto it.

(btw, when i got the laptop i wiped it totally clean and installed winxp sp3, and all with the external monitor connected. had some trouble installing video drivers. never managed to install the ati catalyst driver suite - it always returned a fatal error: no video driver installed. haha! - but installed drivers manually instead. same thing now with my recent tries.)

there was a few variations, sometimes the standby option was grayed out when i switched the computer off and sometimes i got some garbled graphics on the internal monitor when i set the reolution of the external monitor to the same value as the internal monitor. and sometimes i'm not sure is the backlight not working or is the screen blank, but it always works in safe mode or vga and for a long time i tried all kinds of things without the external monitor, thinking that maybe windows or the driver defines it as the primary display, but always with the same results.

can anybody help with this please. thanks.

daniel