i've had my nokia n80 on Three for a month now.
been reading this forum regarding the battery, firmware etc

one thing i can't fix, doesn't matter what profile i've set it to, when i recieve a call the volume of the caller is not as loud as it could be, if i'm outdoors it's very difficult to hear them

anything i can do in the settings?

Er, RTFM? ;)

During a call, move the rocker switch to the right to increase the volume of the caller (and to the left to decrease it)