AF-S Nikkor 55-200 mm 1.4-5.6 ED VR Lens on Nikon D-3100?

I have this lens, bought in October, 2008 that I used until recently on my Nikon D-60 and it ALWAYS autofocused with no problems at all. I recently bought the D3100 and while the kit 18-55 lens autofocuses perfectly, it will NOT autofocus the 55-200. The manual indicates that any AF-S lens should autofocus. Any ideas? Have there been 'upgrades' to the 55-200 in the last two years that would render my 'older' lens incompatible with the D3100? Wracking my brains here. Thanks!