I'm having an intermittent issue with a Nav IV installed on a 2005 1200GS. When starting the bike, sometimes the Nav doesn't finish it's startup routine. Normally when I start the bike the nav starts with a dim gray tone "Motorado IV" screen then goes to a bright "Motorad IV" screen with a note that it is loading maps then it goes to a menu screen and operates normally. The problem is that sometimes it stays stuck on that dim first screen. If I hold the start button down for about 20 seconds the screen will go dark and then the Nav restarts - sometimes successfully and sometimes to stop again at the first dim screen. Sometimes I have to go through this attempted restart several times before the Nav operates normally. The Nav is plugged into an accessory socket on the factory wiring harness so no wierd wiring. I have updated the Nav to the latest software update on Garmin's website. It probably has the original battery but it does hold a charge and it's always plugged in anyway. Any ideas. Thanks.