Here's an idea that improves RAM and CPU performance, after taking a screen shot and automatically saving it, I think KI should program that function (XP and Vista are different in that respect) to clear the clip board contents because there is no need for that image to be taking up space after it has been taken and saved.
Windows handles the clipboard contents. To actually write a snippet of code that interferes with this would quite possibly cause all anti-virus programs to immediately flag Wizard101 as a trojan (virus)...
A specific hotkey for taking screenshots, instead of using Print Screen, would be a far more sensible substitution. Else, if you have issues with the clipboard size, have Paint open with a 2x2 pixel blank square. After taking a picture, alt-tab to Paint and copy the tiny square to the clipboard.