I too bought a TrendNet TEW-424UB. I have the V3.0R model and was looking to get it working with my FC6 installation. I found working drivers on this site
http://www.datanorth.net/~cuervo/rtl8187b/
I used the rtl8187b-modified-dist.tar.gz driver as my kernel is below 2.6.24 and the other drivers complained about the kernel version. Even after making the driver which was a breeze I still needed to get the correct order of commands to make a successful connection. The order that worked for me is:
./wlan0up
iwconfig wlan0 ap xx:xx:xx:xx:xx:xx
iwconfig wlan0 rate auto
iwconfig wlan0 key xxxxxxxx [x] open
./wlan0dhcp
Replace the x's with the correct information for your network. For ap it is the MAC. For the key they are key and Key number. The last command is for getting IP via dhcp which is what I use.
I put the above commands in a script file so I did not have to type them each time I wanted to connect.