Problems installing Configuration Profile

We're deploying iPhones at the plant, and I'm trying to pre-configure them, using the iPhone Configuration Utility. I've created a couple of Configuration Profiles, but cant seem to get them to install. The test phone is an iPhone 4, running IOS 5.The phone has been activated by the carrier, but not configured. I'm running the Configuration Utility on an iMac, under OS X 10.6.8.

When I attach the iPhone, via the USB connector, it show up under devices. When I go to the Configuration Profiles tab and click the "Install" button for a Profile, either nothing happens or I get an error message saying "Invalid Profile". Haven't been able to find any useful help elsewhere on line, so hoping someone here has some wisdom for me.

Thanks,

Don