Bug#583321: Xrandr fails to enable external monitor connected after boot

["Mike B." <mb78aa@yahoo.com>]

Package: x11-xserver-utils
Version: 7.5+1+b1

I'm using a Toshiba Portege 3000 laptop and trying to enable an external monitor on the VGA port. When booting the laptop without an external monitor and later connecting the external then Xrandr fails to set the external monitor. There is just a blank screen and the monitor reports no VGA signal. This happened with two different external monitors (Dell E1910 19" and a Mitsubishi 40" wide screen). When booting the laptop with an external monitor connected everything works fine.

Following http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=495267
I've also tried (with the Dell E1910): 
xrandr --output VGA --off
xrandr --output VGA --crtc 1 --mode 1280x800 --below LVDS

but it just produces a faded and cropped image which later disappears and gives a blank screen.

some hardware data:
laptop uses Intel 945 chipset, 1280x800 Wide monitor

I've placed outputs from xrandr, lspci and Xorg.log.0 at 
http://pastebin.com/adDRZpTZ

Thanks,
Mike.