Hi, I bought a TomTom Go 910 and it was working fine with my MacBook Pro. Now I find that it no longer mounts on the desktop when I plug it in. It doesn't even appear in Disk Utility. If I plug it into my PPC iMac (10.4.9), it's fine again. I think it occurred after installing OS X 10.4.9 on the MacBook Pro, but can't be certain. Any ideas what to do?? Thanks.