I've been having a problem with the last couple of releases, 7.0.2.1 and 7.0.2.2. When I'm zooming in on a project in any of the non-orthographic views, the zooming, in or out, continues after I stop the zooming as if it was set to ballistic or some such (I've checked my mouse settings and they're not set for ballistic). This usually results in something that appears to be the zoom hitting the maximum or minimum zoom at which time it goes to maximum zoom. I'm postulating that whatever is causing the zooming to continue after I stop is causing the zoom value to run past the minimum value and roll over to the maximum. That's the best I can explain it. I find that if I slowly zoom a very small amount to get to a fairly wide view I can get to a zone where the zooming doesn't run away.
If this is of any help, I have an HP notebook with a 3.3 GHz P4 processor, ATI 9000 IGP Radeon Mobility video with 128 Mb Video RAM. 512 Mb RAM, and a basic MS Scroll Mouse that seems to have worked fine with earlier versions of the program.

Is it possible that a new mouse driver has been installed? It might have been done by Windows Update. Windows Update has a log of what changes have been made, it may be worth looking through the list to see if there has been a mouse driver update.

I've been through the Update log and I don't see any recent changes. I must admit that my system is not running optimally at all and it could be any one of a hundred things. My next step is to get my machine 'tuned up' and see if it helps. The problem is intermittent and doesn't always show up and I can still work with 3DC fine. I just have to be careful.