how extend the wireless range of my macbook pro/g5 imac network?

Hi,
I have a G5 imac and a macbook pro (less than a year old). I've been using airport express. The previous airport express signal reached to our basement with no problems. It died under warranty but the replacement doesnt seem to have as strong a signal as I get no connectivity in the basement now.

What's the best way to extend the range of my network?

Will Airport Extreme do the trick even though I have the G5 imac on the network?

My understanding is the G5 iMac wont work with the latest wireless 'n' standard but will with the older standard. Will my macbook pro connect via the 'n' standard and the imac via the older standard or must they both connect via a common protocol and therefore slower and with less range?

Any advice is appreciated.

Mitch

Just for the sake of asking, did you set the power out all the way to 100% on the new one? This is done via the Airport Admin Utility under the "Wireless Options" button.

The new Extreme while being "N" will still do "G" and even "A" for that matter. In other words all WiFi Access Points or Routers are Backward compatible. Try Baggss suggestion also.

Thanks for the responses. The xmitter power is set to 100%. Will the new Extreme run the "n" standard for one machine while communicating to the iMac using another standard?