It's just where it hasn't good good satellite reception and isn't sure where you are for a little while (so assumes you haven't moved much). I get this going through some woods on one of my LSR routes. Because the bit with the tree cover is slightly uphill, I am always tricked into thinking I really have slowed down that much. Then when you emerge from the trees it thinks 'bloody hell, she's got a lot further than I thought!' and assumes you have done a massive sprint to get ahead.
This will sound judgmental (not like me at all ) but I think if a woman feels less (and not more) embarrassed lying on a table with an unfastened bra protecting her 'modesty' while hoping that the cups won't slip off, she's probably really annoying.