By power settings I think he is referring to energy saver in your system preferences. How many networks do you have your machine set to automatically join in your network settings? This can sometimes cause a time out due to conflicting networks. Even it if is not connecting to them it can still cause issues. Also when your connection times out does it connect again and then ask your for your passkey again before it completes the connection? If not, are you having problems with an unsecured or a secured network dropping your connection?
When you enter the passkey make sure to have it save to your keychain, there should be a box above or below where you enter it that will say something like have the computer remember this password.
Also do you have multiple networks setup to your computer? If so, remove as many as you can. You can do this by going into your system preferences and then going to the network option in that menu.
While you are are in the network menu, check to see what your IP address is and what kind of authentication method is being used. Don't post your IP but check to see if after it drops you if its giving you a 169.xxx.xxx.xxx number.
Also are you running Mac OSx 10.7, 10.6, 10.5, 10.4?
few things...check to see if you left your wifi open or someone knows your password and you have leaches. 2. check to see if there more then one wifi in range. most people dont know how to switch there wifi to a non used channel if the default one is overloaded with more then one wifi. 3.check to see if you or your next door pal has a new 2.4g phone. if you do have a 2.4g phone is it near the wifi. (going to jam it) (raspberry jam)...the postion of the router and the ant to your desktop or laptop going to change the range of your wifi. (house has a lot of stone or steel) the biggest dead stop is over and under with the older g type wifi. check the drivers of your wifi card that there updated...on some routers there 3 party firmware that lets you raise the output that the router transmits at.
I have a mac book pro and my internet used to be working perfectly fine but from one to the next day it disappeared i'f tried everything. All the other PCs at my place have no problem connecting. I also see the wifi for a slight second when i turn on my mac(Pro)..