I got my curve today and when trying to send a file (photo, mp3 or contact) via bluetooth it always comes up saying my curve is not responding, i've tried from a Sony Ericsson C510 & LG KC910 (Renoir)
I had this problem as well. What you need to do is go to the folder where you are trying to send to (i.e., Ringtones), then hit the Menu button and select Receive Using Bluetooth. This worked for me.