Alt + Ctrl + Left Mouse Button acting up

Both Windlight and regular viewer, independent of viewer settings
Windows XP Pro, ATI Fire GL V5200 256MB dedicated RAM
I know, I know, you told me not to get it, but otherwise the laptop was *my* dream configuration and I got it on an AWESOME deal, namely 50% off AND I do not regret it. SL is running soooo much better than on my old machine, despite the following annoyance:

I have a very annoying issue with the Alt + Ctrl + Left Mouse button camera control.
Instead of focusing on an object clicked, so that one can move around it with the camera or zoom in or out etc., the camera will randomly do either that or one of the following things:
- move left or right horizontally instead of around the item
- zoom in closely when clicking an item with the mouse when Ctrl + Alt is held
- turn around, i.e. facing in the opposite direction which can be reversed by left-clicking again
- zoom way out and into a random direction leaving me without any orientation
It's weird and unpredictable.

Has anyone else here experienced this sort of Ctrl + Alt + Left Mouse behavior?

I'm pretty certain it's due to the driver settings I'm using. I copied the SL settings from my other computer to this one (same viewer version), but it didn't fix the issue.

I tried different driver versions since SL was unstable at first. With one of the previous drivers I could fix the Ctrl + Alt issue by playing around with the driver settings (Catalyst Control Center), but I didn't know what I was doing, so I guess it was just luck or whatnot.

I finally updated to the latest driver version and it's been the most stable one.

Any suggestions what I should look for? Can it be anything besides SL settings under application data or the graphics settings in the CCC?

Thank you very much in advance for your help!!

Catalyst is really just for video, right? Or has AMD turned it into a beast that tries to control everything? Anyway, I would be curious about what is being used for keyboard and mouse drivers. Oftentimes vendors supply fancy-pants kb and mouse drivers that add nothing over the built-in Microsoft versions but bugs, even if the generic drivers would work fine. Next would be a hunt for any bundled utility programs that "helpfully" remap the keyboard to something strange. And it wouldn't hurt to check that the language and type for the keyboard in the Windows settings match what is really plugged in.

(But make a note of those drivers, because sometimes it isn't that simple with a notebook and you do have to use the vendor stuff)