Plane Sailing
Astral Admin - Mwahahaha!
Firstly, quit being offensive to Vilous please. He recognises that he isn't understanding the rulings and has reservations, but he is at least remaining polite. There is really no call to be rude to people who are not being rude first 
Secondly, I'm afraid I agree with everyone else here V. My understanding (and the way that I've played it) is that the double weapon gets 1.5 Str on damage if you are taking one attack with it, but 1.0 and 0.5 Str on either end if taking two attacks.
My reasoning? Basically everywhere you look the general rule is that the most benefit you can get out of your Str is 1.5 x the damage bonus. Either with 2 hands or with 2 weapons. (perhaps except monks! but the flurry is technically a different thing anyway)
The double weapon is *still* a useful weapon, but from a versatility point of view. You can use it 2H whenever you only get one attack (AoO, Charge, Standard attack) but can switch to 2H whenever you get a full attack. In addition, any weapon specific feats which you get apply equally to both ends - weapon focus, spec, imp crit for instance. So after a fighter makes the initial feat investment it works out as a flexible weapon. The latter effect could be nearly duplicated by using two longswords and quickdraw (to enable you to switch quickly between 2H and 2W attacks as needed), but you would be fighting at -4/-4 instead of -2/-2.
I hope this may have been of some small help
Cheers

Secondly, I'm afraid I agree with everyone else here V. My understanding (and the way that I've played it) is that the double weapon gets 1.5 Str on damage if you are taking one attack with it, but 1.0 and 0.5 Str on either end if taking two attacks.
My reasoning? Basically everywhere you look the general rule is that the most benefit you can get out of your Str is 1.5 x the damage bonus. Either with 2 hands or with 2 weapons. (perhaps except monks! but the flurry is technically a different thing anyway)
The double weapon is *still* a useful weapon, but from a versatility point of view. You can use it 2H whenever you only get one attack (AoO, Charge, Standard attack) but can switch to 2H whenever you get a full attack. In addition, any weapon specific feats which you get apply equally to both ends - weapon focus, spec, imp crit for instance. So after a fighter makes the initial feat investment it works out as a flexible weapon. The latter effect could be nearly duplicated by using two longswords and quickdraw (to enable you to switch quickly between 2H and 2W attacks as needed), but you would be fighting at -4/-4 instead of -2/-2.
I hope this may have been of some small help
Cheers