The mission was temporarily interrupted when the computer inexplicably rebooted. Perhaps they should have used Linux on the embedded Power PC hardware, rather than the proprietary system they did use. From a NASA press release:
PASADENA, Calif. — NASA’s Mars Reconnaissance Orbiter is examining Mars again with its scientific instruments after successfully transitioning out of a precautionary standby mode triggered by an unexpected June 3 rebooting of its computer.
Engineers brought the spacecraft out of the standby mode on June 6. Cameras and other scientific instruments resumed operation June 9.
The Mars Reconnaissance Orbiter reached Mars in 2006 and has returned more data about the planet than all other Mars missions combined.
The June 3 rebooting resembled a Feb. 23 event on the spacecraft. Engineers are re- investigating possible root causes for both events. The new investigation includes reconsidering the likelihood of erroneous voltage readings resulting from cosmic rays or solar particles hitting an electronic component.