anyone have any experience with portable navigation systems?...i have a garmin nuvi360. i turn it on and it always says searching for satelite and never works. it worked fine for a while and then this happened, its happened before and after hours of searching web forums somehow i figured it out but have no idea what i did. cant send it back because i wasnt the original buyer. if any one has any experience or knows a good tech site for this let me know please, heading on a trip soon. tanks