So I recently did a round of upgrades to my 2,1 mac mini. The relevant one was installing lion. My wi-fi connection, particularly the transmit rate has dropped from an average of 54-64 to jumping about between various low rates. It also just disconnects from the router altogether. This has effectively left the connection unreliable at best and unusable at worst. I have reason to believe that the issue is not the hardware. The wi-fi works flawlessly when using windows 7 on the same computer. Also, it's not simply lion because my other mac mini 5,2 is running lion. It is running fine. I've tried all the standard steps. 1) Turning off the computer and modem 2) deleting the preferences. 3) creating a new location and reconnecting to the wireless. 4) repairing permissions. I've googled around and those should have solved my problem. However, I remain stumped. This only cropped up today. My wifi connection was fine with lion for the few days before, just after I installed lion. There have been no significant changes made that I can think of since that installation and the initial upgrades.