I meant for an IV2008 version of your program, i.e. iTweakv2008. I found the registry setting to do this without the program....

That setting, and re-defining the STL values, were all I used.

Yeah there is no 2008 version. I have not found the time to make one. I figured by now ADSK would have put these registry setting into the App Options menu.

All of the options in iTweak are configurable via the registry, correct ? You just provide a user-friendly interface, I presume.

Correct

Commands for reversing the scroll wheel in inventor are as follows, courtesy of Autodesk:

Change the value of Viewing Command Options to 3.

0 = Normal Zoom centered on screen
1 = Normal Zoom centered on cursor (default)
2 = Inverse Zoom centered on screen
3 = Inverse Zoom centered on cursor

Setting it to 0 actually seems to stop the scroll wheel moving altogether.