Team 230 has replaced 2 cRIOs this season:
1). It was fried (likely by metal shavings dropped in from "above"
). NI shipped us a replacement overnight!
2). The second cRIO which was a backup we have was replaced after the Suffield Shakedown Scrimmage where we spent the entire day trying to establish communications with the help of the FTAs and everyone else there. That cRIO had been capable of communications using the old bridge from 2009 but would not connect up to the DLink. When we got our first replacement cRIO it connected flawlessly... and then we had to have some discussions with NI to get the 2nd cRIO replaced.
Note that I can't be sure which was which, but we had purchased one as a replacement for a "lost" system in late March/early April of 2009 and I believe the other was purchased in November/December of 2009 in preparation for the 2010 season.
So... I guess I would say that they were both replaced because they failed.