Lag when panning/rotating with MMB

At work, whenever I use the middle mouse button to pan or rotate, there is about a quarter-second of delay before the UI starts responding to my input (once it starts responding the motion is smooth; I never have stutter or other performance problems). I’d been feeling like something was horribly wrong every time I needed to use the MMB but didn’t put my finger on what until now.

I’m about to throw my computer out the window. I want the UI to respond immediately to my input, and panning and rotating are the most frequent actions I do in Blender. I looked in the prefs but don’t see a way to nix this delay; does anyone know how to fix it? I don’t know if it’s a common problem or not.

Blender 2.67b
i7-2600 3.4ghz
16GB RAM
Windows 7 Professional 64-bit

What’s your videocard?
What video drivers do you have?
What Window Draw Method is set in your user preferences (System tab)?
Does it happen on every file (hint: check after you do ‘Load Factory Settings’)?

EDIT: Never mind, it appears this is a major flaw in the Microsoft Intellimouse Explorer 4.0. I didn’t realize that because most applications don’t use the MMB so I hadn’t noticed the delay before. I can’t find a solution for it.