Problems Installing Rmpi on openSUSE 11.1 x86_64

Dear experts,
having experienced and read on some limitations of OpenMPI with Rmpi  
(https://stat.ethz.ch/pipermail/r-sig-hpc/2009-February/000104.html) I  
decided to try LAM/MPI.
Everything went fine on a Suse 32bit system. Thanks for that so far.

However, on a 64bit machine (LAM and LAM-devel installed), installing Rmpi  
fails. I get:

Try to find libmpi.so or libmpich.a
checking for main in -lmpi... no
libmpi not found. exiting...

Being quite limited in my Linux-skills, I'd appreciate any help.
- Has anyone installed Rmpi on Suse 11 64bit successfully? How?
- (Where) Does configure.ac need to be adjusted?
- (How) Does LAM need to be recompiled to for using shared/dynamic  
libraries?

Thanks to all all developers and active people out there,

Melwin