The distribution name is Fedora 7, not Fedora Core 7 (Core dropped off after 6). And no, it shouldn't have "wireless problems" as far as you have drivers for the hardware.
What settings did you change? It might help to know.
First of all you should make sure that the possible power switch of the card is turned on. If there is no switch, don't worry, but if there is, make sure it's not "off". Then try
/sbin/ifconfig eth1 up
prior to trying to activate the device - it could be that the device is "down", in which case it's not receiving any dhcp messages.
That's a start..if those don't help at all, post the device configuration here.