mod, file was built for unsupported file format which is not the architecture linked

Hi,

I am using gfortran 4.6.0 on Snow Leopard 64-bit to compile some Fortran code that I wrote. The module and object files are generated but when linking the application ld gives the following error message:

ld: in xxxx.mod, file was build for unsupported file format which is not the architecture being linked (x86_64)

I am using the flag -m64 for compilation, so I guess gfortran should generate mod-files for 64-bit (?).

I would greatly appreciate your help with this question as I could not find anything about this problem so far on the Internet.

With kind regards

Lars