Office professional 2007, Windows 7, Lenovo 64 bit computer.

All has been humming along until yesterday. Someone asked me to e-mail a photo -- jpg, 240k. When I tried to insert the photo it locked up and has to use Task Manager to exit Outlook. Ever since, each time I load Outlook, it takes forever, then gives me a window saying it's attempting to connect to the shared database. It eventually tells me it can't connect, and do I want to work offline. I click no, and from then on it works normally (until I exit, then it starts all over again the next time I load). The second time I tried, it inserted the photo just fine and sent it.

I've tried rebooting; I've run Office Diagnostics to no avail. I only use Outlook for e-mail, nothing else. suggestions?