Connecting Linksys Router with Dlink Access Point

I have a Linksys Router (WRT54G ver.6) and am having trouble connecting a Dlink DWL-G700AP access point. The Linksys router is connected wirelessly to 4 pc computers (with Linksys wireless adapters) no problem. But when I try to connect a macintosh computer with the Dlink access point, I can’t make it work. Any suggestions how to find out what the problem is and how to fix it?
Thanks.