I noticed last night that Logitech had released a new version of SetPoint; after my previous encounter (along with the settings that Logitech thought everyone wanted!), I was itching to give them a shot and see if the bug that I reported previously had been fixed.
So, I download v3.30. Yes, that's two released on since my previous test - v.3.10.
And, lo and behold, the bug is STILL present. Great.
Quick test that was; I've uninstalled it again. I can not believe that such a large company can not expend at least some resources into fixing some small annoying bugs with their products. But then again, maybe that's a sign of their size...