Your GPS count looks as if it drops to 7 sats received during the error event. In inverse the HDOP increases to 1.2 up to 1.3 (which in and of itself isn't that bad) but I bet the errors are related to a quick loss of sat count.
You ask how to mitigate. You haven't let us in on how your vehicle is set up. What kind of vehicle is it? How do you have the electronics set up (this is important especially where compass and GPS issues are concerned).
As much info as you can pass along will make it easier for any of us to analyze. The biggest thing here is do you have the GPS mounted on the vehicle directly or do you have it mounted off the vehicle (like on a mast)?