pngcrush 1.6.2-1 has been synced into Dapper from Debian unstable. This
version fixed this bug for me. Please reopen this bug if 1.6.2-1 still
gives the error.
** Changed in: pngcrush (Ubuntu)
Status: Confirmed => Fix Released
--
pngcrush library mismatch
https://launchpad.net/bugs/38011