ubuntu wireless with aes

[Roger Searle]

Hi, I'm looking for list wisdom/experience on making wireless 
connections using wpa2 with AES.  ubuntu 8.04, lspci says the network 
controller is Intel Pro/Wireless 2200BG, connecting to a wrt54gl.  I am 
successful with network manager if encryption is TKIP+AES, but as soon 
as I attempt AES only the connection attempts will fail.  apt tells me 
that wpasupplicant is already the newest version. 

Comments on TKIP+AES vs TKIP vs AES alone would also be welcome, since 
perhaps TKIP+AES is generally very adequate, being more than TKIP alone?

Cheers,
Roger