Ctrl+Shift+Arrow shortcut doesn't seem to work

I only started using Windows 7 a few days ago (new computer, came pre-installed), and I don't seem to be able to select text using the Ctrl+Shift+Arrow keyboard shortcuts (to select text). As this is kinda the mainstay of what I do for a living (writing and reviewing text), I'm understandably upset.

I'm not sure if this is because for one reason or another the shortcut no longer exists in Windows 7 (but I'd have expected more google hits and general hoohah if this was the case), or possibly because I mucked around with the Regional Settings in Windows when it first started. After all, Ctrl+Shift is in there as a possible shortcut to change settings (which suggests a potential conflict). I had initial trouble figuring out how to override the default regional settings Windows came up with and ended up deleting and reconfiguring the settings a few times until I got what I wanted. Maybe I screwed something else up along the way without noticing?

Right now I'm using the US keyboard layout (English native speaker), UK regional settings (date time etc.) but have a German version of Windows, so it was initially set up differently. I've made sure that Ctrl+Shift is NOT selected as a shortcut to change language settings - basically there is only one language set up and all the shortcuts are disabled in the window.

I've also had various accessibility popups triggered inadvertently, and have no idea how I replied to them. I've disabled pretty everything I could find in this respect too (as again the Ctrl and Shift keys can behave differently).

I've got two keyboards, and both have the same issue; I've tested one on an XP machine, and the shortcut works fine there - so it's not the keyboard.

I found someone else asking the same question elsewhere on the net, but couldn't find an answer...

So:
Does the shortcut still exist (I'm assuming it does)
Any idea how to get it back?