"GPS lock cannot be obtained"

[Robert Glenn]

I bought a new tablet and installed AvareX, and I'm pretty reliably getting this error whenever it doesn't have an internet connection (i.e. airplane mode).  Obviously this is a problem in the cockpit.  I don't think it has anything to do with hardware or GPS reception, because I installed "GPS Test" and it can reliably get and keep a fix fairly quickly, even indoors.  In fact, if I switch out of Avarex and run "GPS Test" and then switch back to AvareX, it will have a GPS position, but only for a few minutes, and then it'll be back to "GPS lock cannot be obtained".  Anybody know how to troubleshoot, or work around?  Thanks!