Mac Mini OS X 10.4 Dropping Wifi [updated]

OK, so this has been bothering me for a few weeks now, but the front room mac mini has been incredibly flaky with wifi lately. Like, proper flaky...maybe up 1 minute, 1 hour, 1 day and then drop for no reason whatsoever, refuse to reconnect....but then sometime later mysteriously connects.

It seems that the solution is to delete the AirPort preferences file in /Library/Preferences/SystemConfiguration (com.apple.airport.preferences.plist) and let it be regenerated.

Shall try that tonight...fingers crossed.

[UPDATE: This does not work]