I would like to inform you that we have investigated the issue closer and were able to identify the most possible solution. Most probably, the issue is related to hanging of Mac OS Sync Service after update to 10.7.4, and could be fixed by the correct restart of the driver. Please check the detailed instruction at the Apple Knowledge Base:http://support.apple.com/kb/TS1627
The correct solution from the link is below:
"Hold the Option key on your keyboard, then click the Sync menu in the menu bar:
if you see the Sync menu but you are unable to open it, skip to step 8.
Choose Reset Sync Services.
Click Reset Sync History.
Test for the original issue. If the issue persists, or if you are unable to open the Sync menu, follow these steps:
In the Finder, choose Utilities from the Go menu.
In the Terminal window, type or paste the following command on a single line:
When the operation is complete, quit Terminal."
Then let us know if the issue persists. Thank you.