I, too, have encountered the same problem. I was able to use TomTom Home in conjunction with the TomTom 910 without any issues up until just recently. Am still trying to figure out what happened to change this. As far as I can tell, there were three different software updates that occurred around the same time and perhaps one or more of these updates contains a bug that prevents us from using the product at this time. TomTom issued two of the three updates - one to their 'TomTom Home' software application, and one to 910 GPS device itself. Apple released one update - that being the OS update to 10.4.9. At first, I had thought that my sync cradle for the TomTom had gone bad, but was able to sync without a problem using my Windows PC. It seems to me that either Apple or TomTom forgot to include the driver(s) with one of their updates here. Don't know for sure - but am leaning towards it at this point.
My Tomtom Get Started Download Now For Mac
Note: The following navigation devices do not connect to HOME: GO 800/1000/2000 series, GO LIVE Top Gear edition, Via series, Start 20 series, Start 60, Blue&Me TomTom 2 LIVE, Sony XNV, TomTom Connect, GO 40, GO 50, GO 51, GO 60, GO 61, GO 400, GO 500, GO 600, GO 510, GO 610, Rider 410, Rider 400, Rider 40, GO 5000, GO 6000, GO 5100, GO 6100, Trucker 5000, Trucker 6000, START 40, START 50. The program for my Mac says downloading updates, but never does. It says the servers are busy. Haven't been able to update in weeks.