iMac G3 (slot-load) 500 mhz - Airport card cannot connect to DIR-655

Hi

A friend of mine gave me a iMac a couple of weeks ago. i upgraded the RAM to 1GB and I bought a Airiport Card (802.11b)
I plugged in the card and attached the antenna to the card and tuned on the mac. But when i try to find a wifi network (mine for example) it won't connect. Im using a DIR-655 Dlink router. i have mixed mode emabled (802.11b/g/n) and WPA-Personal Encryption (AES Cypher)

Why is it not connecting?

PS the message i get when i connect is "There was an error connecting to network [network name]"

Thanks

I will try your suggestions there. I hope this doesn't solve the problem because i do use n (macbook pro)

Well it looks like worst case scenario has happened. It seems that the network is working if i put the router in mixed mode b/g and if i disable encryption. but if enable encryption the mac will not connect. I hope i don't have to to leave the network open. I could create a subnet so the the DHCP will only except 16 host IP's but don't have that many PC's/wireless devices.

Any who, thank you for the fix there 007 i'll have to find out if the airport card is out of date (which i don't think it is [9.5x] but the software might be out of date. (BTW the encryption is obviously WEP but i know iMac G3 supports WEP so why is it still not working???)