Autoconnect to Airport Network Fails


I have had the following problem for the past 3 weeks. I have tried numerous suggestions, none have worked.

I have an Airport base Station Extreme with iMac 800MHz LCD 15" original running Mac OSX 10.4.2
I have ABS as my primary airport network named "apple001aw". I have the airport icon in the top menubar.

Every time I set the iMac to Sleep and then wake it or else Restart the system, the airport icon is grey bars not back bars - not connected automatically to "apple001aw".

I have worked with Preferences - Network a lot trying every combination imaginable. Nothing seems to make the AutoConnect (connect Automatically to preferred network, and add using "+" only apple001aw) work. But it definitely worked in the past even with 10.4.1. But I lost track of what System or Security update or other (small) software tools has resulted in this state of affairs.

Please assist. Thankx