Larry Dighera wrote:
http://www.newscientisttech.com/chan...e-for-gps.html
Solar storms spell trouble for GPS

SOLAR flares can drown out GPS signals with potentially serious
consequences for airlines, emergency services, and anyone relying on
satellite navigation.
....
How was such a clash missed? Because GPS receivers only became common
during a period of low solar activity. By 2011 solar flares will reach
the peak of their cycle and receivers will likely fail. ...

Of course this newsgroup was alive and well during the last solar
maximum and there were no widespread failures reported. Sam kept us
informed with the bulletins on current solar activity, but I noticed
only minor effects on my consumer-level GPS receivers. I still have
the tracklogs recorded in 2000 during the maximum and they don't
support the dire predictions of the above article.