appear to be susceptible to "Cones of Silence", where the GPS stops working !!
Perhaps the tablet was busy doing other things?
I had that happen with a netbook running some (ground/ road) navigator software and the GPS just stalled and the map didn't advance.
Later (after getting lost and reverting to paper) I tracked it down to the fact that the anti-virus checker had decided to do it's thing (full disk scan) thus tieing up all the PC grunt!