In case it helps the next guy, a workaround, suggested by the author of the envlab package:
For each problem character, place a line like this in the preamble: \PrerenderUnicode{\"o} and enclose each such character in {} where it is used in the body of the document: Gr{\"o}nstr We successfully used the actual unicode character, rather than a the \"o construct, in both places. De -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org