I've got my MX Rev set to scroll horizontally when the scroll wheel is tilted left or right. It works in other apps, but not in DOpus 9.1.1.7.3307.x64.
What happens is that the scroll bar turns from the cool Vista scroll bar to the ugly classic scrollbar. Then the ugly scroll bar moves from side-to-side (as expected). But the view in the Lister doesn't move with the ugly scroll bar (unexpected). The view never scrolls. Hovering the cursor over the scroll bar, or clicking on it, restores the cool Vista look (and the original position of the scroll bar).
Manual manipulation of the horizontal scroll bar works as expected. Vertical scrolling with the wheel also works as expected.
Using Vista Businsess x64.
SetPoint Software version 4.70.213
No WindowBlinds or other customizing software is in use. 9.1.1.6 did the same thing.
I returned to Setpoint 4.6x because I found out some global problems with 4.70. Also there was a Setpoint 4.70-version 1-2 months ago online for only a few days, then Logitech removed it. Maybe you have downloaded this "beta" version.
Thanks again for the info about problems with some versions of SetPoint. I reverted to the 4.24H drivers that came with the mouse, and now horizontal scrolling works as expected in DOpus.
4.60 should also work fine (tested with MX Revolution/1000/510/518/410).
Maybe just a setting needs to be changed to get Setpoint 4.70 working with DO (like middle button). But I didn't try that because the speed/precision of the mouse is (in my opinion) different than in 4.60 and I don't like it.
It's got a digital signature from Logitech, stamped a few seconds after the 4.60 32-bit installer that I already had a copy of, so it's legit. (Or at least was when I downloaded it. Best to check the digital signature yourself just in case. )
)