Just for a double check, make sure the wheel button is actually set to 'middle button' in the SetPoint mouse driver. You may want to add SW as a custom setting in there even if you leave all the settings to default just to keep it in line if you happen to change some of the mouse settings for other programs.
I use the older MX1100 (even more buttons) and find that the wheel button is actually pretty hard to push. It's even harder to push without accidently activating the tilt clicks. On mine if I tilt click left and middle click at the same time it pans the model.
You might also want to have a look at uberOptions. It is SetPoint on steroids. Adds many options for button settings. I set one of my thumb buttons to 'esc' for example, eliminating a trip to the upper left keyboard for my left hand. My left wheel tilt is Undo. I also set a couple buttons as Copy and Paste. Little things like that can eliminate a lot of arm waving over the keyboard which can really speed up the modeling process.
The wheel is set to 'middle button' and I even had an IT man helping for about 1 hour (at a price) but could not sort it out. Yet, if I set any other button to 'middle button' it works perfectly and I can rotate the model. I have no idea how or where to add SW as a custom setting and I never 'customise' my mouse.
I feel that my best option at this stage would be to return the mouse and get a refund.
Perhaps if the issue is solved in the future it would be nice to know.
Just had a play and found something very strange. Even though the wheel was set to left scroll, middle button, right scroll, when I pushed the button to right scroll I could rotate the model. SO I reset both left and right scroll to middle button and it works fine. I can now rotate the SW models.
As I have never used or needed to use the left and right scroll settings I am happy the way it is.
I have a Logitech Wireless mouse and I had a problem at first.
I now have the middle button set to 'Other>generic button' and the middle button rotates fine in SW. Don't think I used a specific set up for SW but it was a while ago now.
I'm noticing since last windows' update (8 updates) this morning, mouse movements aren't working properly and SpacePilot Pro is disabled.
If there is no fixing update to todays update, I'm thinking of going back to an earlier restoring point on Monday.
Same happend to my home computer few days ago.