What you have is a common configuration which is called a 'switch loop'. Power comes in on one cable with the black then connected to another cable which takes the current down to a switch, returning it on the other wire in that second cable.
Connect the white from the fan to the white from the power source. Connect the black and black/white to the white from the switch. Connect the green to the other grounds (usually bare wires in the box.
The fan should then operate as before, with both the fan and light turned on and off by the switch. (If no light fixture is to be installed, do not use the black/white striped wire)

Thanks Randy, I'll give it another try after I get rid of this mornings frustrations! : )

Teresa

Technically the switch loop is wired backwards... it's defined in order to avoid exactly the same problem you just encountered.

Got it running! Thanks so much for clarifying for me! : )

Teresa