Wireless incompatibilities

I am trying to make an Aironet 4800 access point work with an SMC wireless nic. The access point will show that it registers the nic but I cannot ping any tcp/ip addresses consistently including the access points’ address. And sometimes I can. The AP is 30 ft. from the PC’s with no obstructions. I have tried everything. Are these two devices compatible? Are there any settings on the AP that will allow for a more stable connection?