I am using powerdot and ppchtex two draw some chemical structures. Since the new version of hyperref (6.76e), it no longer works. The problem seems due to the order of loading: if ppchetx is loaded before hyperref, I have no troubles.
I tried loading it before loading powerdot (using: \RequirePackage{m-ch-en}) and that doesn't resolve your problem. This is a hyperref problem. Report it there please. -Hendri.