Good day Rossco,
Thank you for your forum post. We have just responded to you via Zendesk and have also copied and pasted the reply below for others who may be experiencing this issue.
I just did a quick Google Search for the issue you're having with SketchUp and managed to find this article by SketchUp which provides you information about your scroll wheel, mouse clicks etc.
In the article, they provide instructions on how to adjust your Scroll button:
1 - Select Window > Preferences.
2 - In the sidebar on the left, select Compatibility.
3 - In the Mouse Wheel Style area, make sure the Invert checkbox is UNticked.
4 - If it is ticked, untick it, Click OK and see whether the scroll problem has resolved.
I've also found a forum topic in SketchUp where other SU users have had problems using 3D Connexion space mouses; some users can't connect their mice after updating SketchUp, and other have the same problem as yourself. Check out the article below as they also provide additional links that may help you out:
3D Connexion Mouse not working
Feel free to respond to the SU forum as it's a great way to connect with other SU users to help solve common/not-so-common issues in SketchUp! It's also the No.1 place I go to whenever our customers experience issues such as this.
We are happy to assist if you have any further enquiries.