SharePoint 2010 Profile sync services uses Forefront Identity Management services. To troubleshoot the sync process you can use Forefront Identity Synchronization Manager Client UI in:
[Install drive]:Program Files\Microsoft Office Servers\14.0\Synchronization Service\UIShell\miisclient.exe
This tool has so many details its hard to figure out at first. Once you click around you can find the AD mappings. This can also be used to sycn with other sources other than AD.
If you click on Management Agents, then Double click on MOSSAD-[domain], you can see the AD Mappings rules.
Once i create and test a new agent i will post the details.