[plt-scheme] Plugin-based software

Hi all,

I'm trying to implement a simple plugin-based software. My first
approach which quite didn't was to define a plugin as a plain scheme
file where the last expression was a unit which imported a given
signature. Then I have a master file which loads the plugin with
'load', composes the plugin unit with another main unit and invokes
what it needs. Seems ok at first but the problem is that the plugin
may require some lib functions so it start with a couple of
'require's. For some reason it runs ok inside DrScheme, but when I
compile the main program and run it, it tries to load the plugin and
then I get an error message along the lines:
Couldn't find collection "srfi" in HOME/.plt-scheme... etc etc.

Oh, well, so I though I should compile it. I did so using the
compile-file and the I used 'load' again and load returns:
compile: variable not provided (directly or indirectly) from module:
mzbrain in: begin

well, can't understand this. mzbrain is the main module. I'm just
trying to load a files primefactor.pss.zo. Can't understand it's
problem. Any guesses?

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