LCD Display problem when connecting Camera to computer

[Diablero]

I bought today Powershot A75. Seemed everything worked properply until i wanted to transfer images to PC. I installed all the software distributed in standard package, made all necessary steps and here the problem: When i switch camera to communication/browse mode after connecting turned-off camera with USB cable to computer, and then turn camera on, the CameraWindow application is starting and at the very same moment LCD display of camera gots turned off! after this the CameraWindow gets crashed - it cannot find camera connected to Computer. turning off- and on again doesnt help. I tried to reinstall all software, got newest TWAIN driver and ZoomBrowserEx Application Update from internet - NOTHING!
The same problem: when i try to connect to camera from ZoomBrowserEx, camera's LCD display gets turned off again and i Got error dialog that application cannot find camera!
In hardware manager the Canon Camera is present - it is installed and the driver seems to be ok...

Does anybody have any idea what the reason could be? Is it software or hardware problem??
(I Have Windows2000, USB1.1, Camera has new batteries...)

Help me please...

Thanks

[S45_fornow...]

%m

[Jon]

W2K should work OK. IIRC, shifting to Camera Mode should open the CameraWindow application, and shut off the camera's LCD. ZB should do likewise.

Are you using rechargable or disposable (alkaline) batteries? The different voltage and current capacities may make a difference.

Are you plugging the camera directly into the computer (laptop or desktop?) or are you connected thjrough a USB hub? If a hub, does it have a power supply, or is it relying on power from the computer? Do you have any other USB devices plugged in at the same time? Do they all work normally?