I was having this same problem. I wanted to transfer images from my Motorola Droid to my MacBook Pro. They paired easily, but each time I told the image to send, it ended in error, or just wasn't sending. In the end, I gave up turned off my bluetooth on my Droid. But then, and I can't remember why, I turned it back on, and suddenly my Mac starts receiving the files (a few copies because I kept trying). I didn't have bluetooth sharing on before I paired, and that might have been the problem. I just tried sending more files, and things are working now. Both directions.
My settings:
On my Mac:
"Bluetooth Sharing": on (obviously)
"When receiving items": Accept and Save (so you don't have to accept each time)
"Require Pairing": checked (so only your devices can send you files, wanted with above setting)
All other settings on your Mac bluetooth sharing shouldn't affect sending files.
I didn't do anything special on my Droid.
So if at first you don't succeed, try turning off your bluetooth on your phone, turn it back on, and hopefully things will work for you like they did for me. You'll probably have a better try if your bluetooth sharing is on before you try and share.
My settings:
On my Mac:
"Bluetooth Sharing": on (obviously)
"When receiving items": Accept and Save (so you don't have to accept each time)
"Require Pairing": checked (so only your devices can send you files, wanted with above setting)
All other settings on your Mac bluetooth sharing shouldn't affect sending files.
I didn't do anything special on my Droid.
So if at first you don't succeed, try turning off your bluetooth on your phone, turn it back on, and hopefully things will work for you like they did for me. You'll probably have a better try if your bluetooth sharing is on before you try and share.