I have a blackberry 8830 that paired fine.

the problem is that I can barely hear my caller....the volume on the 8830 is fixed at 50% when in blue tooth mode (which I cannot increase when blue toothed...I do not know how to make the Z2 enhance the callers volume any louder, the phone setting on the Z2 is already set at max.

I have looked around this site for ideas but so far nothing that helps.

Any ideas?

there is a volume button in the menu->settings submenu, you can set the caller volume there. Not too loud, otherwise your caller will echo.