...do you have the latest versions installed ? Yesterday a whole new 'EOS Utility Disk' was launched, new versions for Windows (for Vista Sp1) and for MAC:
From RobGalbraith:
Headlining the list of changes is the addition of 16 new lenses eligible for the lens aberration correction function in DPP 3.4.1,
while Canon shooters on the Mac will welcome the fact that both it and EOS Utility 2.4 are now promised to be compatible with Mac OS X 10.5.x (which means, among other things, that tethering capability is restored for some though not all digital SLRs).
The link...
...FWIW, *my* €0.02...
Kindest regards!
Max@Home