Approximately twenty figures were suffering from some form of plastic bend out of my Mars Attacks Kickstarter, including most of the US infantry, the vast majority of whom were suffering from bent barrels on their M16's.
I was a little disappointed with this, but decided to hold off complaining until I tried the old trick of immersing the figure in boiling water, then hoisting out (with a spoon!), bending the bent bits back into position, then plunging into some icy water to set the straightened pose.
Luckily, not even that amount of effort was required, as soon as the figures were put in the hot water, the bent parts immediately straightened of their own accord. A quick plunge into the ice cold water and they set back in their correct position.
Presumably the plastic retained some pose memory from after the casting process and I am now happy with the end result for some very minimal effort.