From what I just read in an article, the Spirit Rover needs to reboot more that Windows NT 4.0 in order to allow it to function correctly.
Apparently, much of the problem with the Spirit Rover was due to the fact that the onboard flash memory filled up. When it was out of space, the system would reboot. It took until just recently to get the data cleared out to repair the problem.
The other thing I read is that it transmits at 11KBps. I’m sure that makes the dial up users happy… the thing is almost 5x slower than their connection. No need to complain any more!