Do not bend them them too often at the base, or they may end up like this.
When an extender doesn't work look at the soldering job under the tape before going crazy with your motherboard and OS.
See the 1st pin, it's not soldered but worked sometime.
Then you may have to do the A1 B17 mod, shown here https://bitcointalk.org/index.php?topic=36061.0
Be careful not to overload you motherboard's 12v by adding more than 4 gpu without additional power sent via the extender.
Lots of good info at : http://blog.zorinaq.com/?e=42
Best of luck.