I received my Tomtom Navigator 5 BT receiver a few weeks ago and it worked pretty well. However, when walking in my neighborhood where there are a lot of tall appartment buildings, it was flaky. It would flip-flop the direction it thought I was going too often to be useful. I did some searching and found www.gpspassion.com and found a wealth of information on Sirfstar III GPS receivers which is what the Tomtom BT receiver is. A feature called "Static Navigation" was enabled in my unit and this caused the problem I was having. I found a program that allowed me to disable this feature and it now works much better. It determines the correct direction quickly and locks solidly on it. Here is the link to the program and a tutorial on how to use it. The program is called Sirfdemo.