[plt-scheme] osx embedded app and mzlib

i'm trying to make an osx application of a program called fluxus that
embeds plt scheme. i included the PLT_MrEd framework in the application,
as well as some plt modules that seem to be required: compiler, config,
defaults, frtime, lang, mzlib, mzscheme, scheme, setup, srfi, stxclass,
syntax, xml.

when i run the application it exists with the following error message:

Applications/Fluxus.app/Contents/Resources/collects/mzlib/unit.ss:1460:38:
syntax: no pattern variables before ellipses in template at: ... in:
((import i.s ...) (export e.s ...) dep . body)

i'm using plt 4.1.5, it seemed to be working fine with 4.1.4.

any help would be appreciated.

thanks,
gabor