Ok, before I describe the problem I think I must give you some background info.

1)I'm a Linux newbie. I've just installed the Fedora Core 6 Linux distribution.
2)I've installed the MPICH2 program (contains libraries for parallel algorithm programming) <-- double and triple checked: No problem in the installation.
3)I'm working with KDevelop. I can compile and build simple C++ programmes without problem.

But when I use libraries from MPICH2, I get the following error message during the build:

undefined reference to `MPI_Init'
undefined reference to `MPI_Comm_rank'
undefined reference to `MPI_Comm_size'
... and the list goes on ...

How is it possible that the KDevelop compiler recognizes these (functions/procedures(?) whatever) during compilation but not during build?

Anyway, I'm not expecting that any of you has used this specific program, but I guess that you'll have encountered similar errors in other cases too and dealt with them.
PLEASE HELP!