bluetooth headset problem

I got a vx9900 woo, and then i got a bluetooth set with it. I put the bluetooth with my 9900 and then my 9800, and then tried to put it on my 9900 again and its not connecting, like when i have my 9800 visibility on and then when i turn the headset on, it trys to connect to the 9800 right away, but not the 9900, i turn off my phone, dced the battery and went about 30+ feet away and it still doesnt work, the headset i got is the bt135.

thanks

Is it still synced with the 9800? Turn it off.