Disabling an annoying keyboard shortcut in Windows XP

I use keyboard shortcuts quite extensively in Windows XP, and there is a certain key combo that annoys me.

When selecting a block of text, you hold the shift key + left or right arrow. To speed it up, the CTRL key can also be pressed to go right or left by word, instead of by letter. Well and good.

There are times when I just press CTRL+Shift without the arrow key. When this happens, the text suddenly goes to the right (if I pressed Right Shift, Right CTRL). This messes up the selection afterwards, and can be remedied by pushing Left CTRL and Left Shift.

So, I just have 1 question. How to disable the Right CTRL + Right Shift keyboard shortcut in Windows? I've done a cursory check, and all of the tutorials don't even mention this thing.

Thanks in advance!

Jam it back in, in the dark.