iPad 1 Not charging with anything but the included iPad cable

[salils]

After the iOS5 update (now on 5.0.1) I've been having problems charging my iPad 1 (as many others have). SOMETIMES I can get it to charge using a cable other than the $20 Apple one but usually it doesn't work. What gives? It used to work so these cables are clearly capable of handling the extra current the iPad draws. Also, my iPad refuses to charge via anything except the Apple wall charger after the update. I have non-apple 10w chargers that would charge my iPad at 2A before the ios5 update. Another weird thing: I can sometimes charge my iPad with the Apple iPad cable on a non-Apple charger. How can I fix this? I've just about had it with waking up to find my iPad hasn't charged to the point where I'm considering switching to Android and that will be very painful as I tried it already with my iPhone and had to switch back.

ALSO: I use USB extension cables running from my wall chargers to my bed and my iPad will NOT charge if I use an extension anymore (even if I'm using the included Apple charge cable on the end of the extension). It's really impractical having to be huddled up near a wall to use my iPad while it charges.

 

[Kaykaykay]

My iPad 1 continues to charge fine with non-Apple cables, but I don't have off-brand cables or chargers (like from eBay). I have chargers and cables from Griffin and they continue to work fine with my iPad 1 and 2, iPhone and touch after upgrading to 5.1.1. The cables and chargers worked fine on all lower versions of iOS, too.

 

[Kaykaykay]

You could just use a regular extension cord and plug your Apple charger into that, rather than huddling next to an outlet.

I tried a long USB cord about two years ago, when I first got an iPad, and I found it charged, but slower than with my Griffin PowerBlock alone, so I just switched to an electrical extension cord.

 

[icope]

I have found it all depends on how low the battery is. That's why the non apple cords work only sometimes. Have no idea why but I have definitely seen that be the case.

 

[salils]

Update: I found some cables such as this one:
1PCS Keychain USB Charge Sync Cable Adapter For Apple iPhone iPad iPod New Gift | eBay
Work fine for charging as well as some extension cables that work some times such as this one:
2.0 USB Extension SYNC Cable Cord for iPod iPad White | eBay
Why do only some cables work? Anyone know what's going on here electrically???