I have found an alternate, but equally effective method of fixing warped figures. This has worked not only on D&D minis, but on HeroClix as well.
Get out a hairdryer and set medium heat. Hold the figures in the heat for a minute or so (I just use double-sided tape and some scrap cardboard). They will become pliable fairly quickly. Position the figure to its proper pose. At this point you can either set them aside (works best for HeroClix) or do a quick dip in cool water. This will set the pose in place. The harder the plastic type the longer the heating and cooling process will take.
Get out a hairdryer and set medium heat. Hold the figures in the heat for a minute or so (I just use double-sided tape and some scrap cardboard). They will become pliable fairly quickly. Position the figure to its proper pose. At this point you can either set them aside (works best for HeroClix) or do a quick dip in cool water. This will set the pose in place. The harder the plastic type the longer the heating and cooling process will take.