Admittedly Cisco (Aironet/Telxon) and Symbol encryption (WEP, EAP and LEAP) are not handled very quickly. Your best bet is not to do any encryption at the access point. From a security perspective there is little point anyway as they are all based on RC4, which is a poor algorithm. WEP can be broken in a matter of hours, and EAP and LEAP just increase the time needed.

All major 802.11b vendors agree - use IPSec if you want some degree of protection from hijacking, sniffing or unauthorised access. Using MAC ACL's obviously helps as well, and from my experience I would never run an 802.11 WLAN without a firewall between it and my LAN as they are so trivial to crack.

OOOps - went off on one there. My main point was to avoid using the encryption offered by the Wireless device, and do all that CPU intensive stuff on a fast CPU or not at all (depending on security desires.)