We have 2 Powerbooks and 2 iMac G5's in a small office using a Linksys Access point. The 2 Powerbooks have nice strong signals (between 3 and 4 bars) but the iMac's only get 1 or 2 bars and quite often have no signal at all. If I put the Powerbooks near to the iMacs, the laptops will have a...