[plt-scheme] Loading compiled extension modules with R6RS (import)

Hi,

I have made a MzScheme to LLVM wrapper using the C API. I can load and 
use the module fine using the non-standard (require) form. However, I 
cannot manage to load my extension in R6RS mode.

I have tried many permutations, based on:

- http://docs.plt-scheme.org/r6rs/libpaths.html and
- http://docs.plt-scheme.org/inside/overview.html (the parts relating to 
load-extension)

I am using MzScheme v4.2.3 (3m mode).

<plug type="shameless">
For those interested, the code is at http://github.com/jothan/mzscheme-llvm
</plug>

Any tips on how to get this working are greatly appreciated.

Cheers,
Jonathan