Some times my gps will go hay wire and I'm not sure what is causing it. I can be driving along and everything is fine and then all of a sudden my arrow will go off course and finally reach a road I'm traveling adjacent to. My gps then thinks that it must lead me back to the current road that I'm on but it never gets there and it just stays off course. It's very annoying, especially when you have it set for a destination and it never finds it's way back on course. I have a F90bt with the hardware bypass done and running the 3.0 update. If anyone has ideas on how to correct this information, please post and let me know. Thanks in advance.

Did you try resetting the unit ? Also do you have the antenna where it's getting a good signal ?

Bad timing circuit in the GPS receiver.

I haven't tried doing a reset yet, but I will give that a shot.