[plt-scheme] Plugin-based software

I'm still around this problem. I've tried to simplify the issue to
find out what the problem is. I'm afraid it's a compilation bug by
scheme.
After compiling the file (with compile-file) to
.mzbrain/plugins/primefactor.zo:
http://sat.inesc-id.pt/~pocm/archive/primefactor.pss

which compiles fine I try:
 (dynamic-require (string->path (string-append (path->string
(find-system-path 'home-dir)) ".mzbrain/plugins/primefactor.zo"))
                   'plugin)
. link: broken compiled code (phase 0, defn-phase 0, in primefactor),
no declaration for module: mzbrain in: begin

Any suggestions?

-- 
Paulo Jorge Matos - pocm at sat inesc-id pt
Web: http://sat.inesc-id.pt/~pocm
Computer and Software Engineering
INESC-ID - SAT Group