Scroll wheel bugged in WPF applications

I have an issue that on one computer applications developed using the Windows Presentation Foundation have my scrollwheel all inverted. I scroll 'upwards' and the control in question will go down. And vice versa. Other programs are not affected and scroll just fine.

I have searched a lot, but I can't seem to figure out what might be causing it. I am using W7 64-bit.

Things I have tried or might be useful to know...

• creating an application using Winforms as well as a plain Win32 api. In those, when I scroll down, it scrolls down. All is well there.
• I have also tried one of the affected applications (which I myself wrote) on my WXP 32-bit laptop. On that one, scrolling down indeed means scrolling down.
• I use the standard Windows mouse driver. No fancy Logitech or other software installed that might be causing this.
• This Windows installation is 2 months old or so. There is very little, if no cruft. I have no doubt that if I reinstalled, I'd manage to trigger it again. (I never had this issue before because prior to this I ran XP and avoided .NET like the plague.)

Anyone have any clue what setting is hiding where that's messing my WPF applications up like this?

Edit:

The fo开发者_如何学编程llowing, when put on a populated listview, gives the correct message (down for down scroll, up for up scroll), yet it will still scroll in the wrong direction. What the hell?

private void listView1_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
    if (e.Delta < 0)
        textBox1.Text = "PREVIEW DOWN WE GO.";   // no we end up going up :(
    else
        textBox1.Text = "PREVIEW UP UP UP.";     // big letdown here.
}

(The plain MouseWheel event won't fire, hence the preview variety.)

Holy crap, I just figured it out. It suddenly hit me.

I have me Mouse wheel set to 'scroll one screen at a time'. I never thought anything of it despite going over that window a dozen times looking for an 'invert scroll direction' option I might have checked.

Setting the setting to scroll a given number of lines per notch on my wheel fixes the scrolling, although I don't get my expected paging.

This is plain buggy coding on Microsoft's part. First I spend half a day searching the internet for TextOptions.TextFormattingMode="Display" so my forms don't look like total crap, then I spend a small eternity on another issue which thankfully had a simple setting suffice as well. And now this. Am I just hitting all those little roadbumps nobody else seems to hit or care much about? :/

(Apologies for answering my own question again, kind people. I've done it the last few questions despite searching for answers on the matter for hours. Ugh.)

There is absolutely no reason for this to happen. Have you tried running the problematic application on other computers.