I'm just started using Fedora 3 on a Thinkpad 600E and ran into this problem. At home I have a Linksys WAP11 802.11b access point that uses WEP. The Thinkpad uses a Senao 2511 CD+ EXT2 802.11b PCMCIA card. At installation, Fedora 3 recognized the card and configured it correctly. Everything worked great. My ifcfg-eth0 looked like this:

DEVICE=eth0
BOOTPROTO=static
BROADCAST=192.168.0.255
ESSID=wireless
IPADDR=192.168.0.200
KEY=0123456789
NETMASK=255.255.255.0
NETWORK=192.168.0.0
ONBOOT=yes
TYPE=Ethernet

I then connected the laptop to a public wireless network that used DHCP and no WEP. I made a copy of my original ifcfg-eth0 and named it ifcfg-eth0-original. I then changed the settings of ifcfg-eth0 to the following:

DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
TYPE=Ethernet

Everything worked great. I connected to the public network and got an address with no problem. When I went back home I deleted the ifcfg-eth0 file and renamed ifcfg-eth0-original to ifcfg-eth0.

The card connected to the access point but wouldn't associate even though I was using the same parameters that I used successfully before. Interestingly, I can't ping the access point (192.168.0.1) but I can ping the Ethernet card that the access point is plugged into (192.168.0.5).

Any ideas would be most appreciated.

Moved: This thread is more suitable in Wireless Networking and has been moved accordingly to help your thread/question get the exposure it deserves.

resetting and reconfiguring the access point seemed to fix the problem.