same problem two times here. were running 3dconnexion devices on 14 machines.
5x space mouse plus usb -> no problems in about 4 years
4x space explorer -> 1 with the problem described here
5x space pilot pe -> 1 with this problem
tried a lot of things including a pci usb board and all the solutions described here with the explorer. well, it works most of the time but the problem still shows up sometimes.
since today i have the problem with my personal space pilot at home and will now try to solve the problem. it worked well for a week but this morning -> nothing. tried to reinstall the driver, cleaned the registry, replugged on different ports already. didn't help.
you're not alone
 i tried different space explorers on the machine with the problem. it happens to every explorer and just on that machine. they work perfect on other machines. anyway: it's a 3dconnexion problem, software or hardware, as it must not be that those devices just work on 80% of all pcs...
[edit2] for my home machine with space navigator: the path in the link didn't change automatically. there is no error as i have no log file (in the new %appdata% path). tried to run 3dxsrx.exe from the console -> no error or any other message.
[edit3] (home machine with space navigator). replugging didn't work as long as the normal mouse was still plugged in. also doesn't work when doing a port change and unplugging both and plugging in the normal mouse first. BUT:
solution (hope it lasts
) : i changed the usb ports of the normal mouse and the space navigator. it worked this way:
- unplug both
- replug the navigator in the other port
- then replug the normal mouse anywhere
didn't even have to restart the machine... will write if the problem reappears.