Bluetooth Pairing in Iphone 2G

hi,i just inherited an Iphone 2G from a close relative who decided to switch to other brands..I'm having some problems with the bluetooth pairing to another device (another cellphone) in my Iphone..i'm trying to send a picture or mp3 file from "Cellphone A" to my iphone but the iphone cannot detect "Cellphone A"..however "Cellphone A" CAN detect iphone..Again i tried another "Cellphone B" to pair with iphone,still same problem...though "Cellphone A" and "Cellphone B" can pair with each other perfectly..Can anyone enlighten me on this problem??Current OS 3.1.2..