missing fileinformation with memprof

I'm triying to find a memory leak with memprof. I'm using in environmet.rb:

Memprof.dump_all('/tmp/test.json')

after uploading to memprof.com I can see following:

    * objects with most outbound references

2318 classes and 384 modules

    * namespace hierarchy     * class hierarchy     * instances per class     * duplicate classes by name

497 source files

    * 6547 objects created inside eval     * 22571 objects missing file information <--------------

299912 nodes

    * nodes by type     * nodes per file

I have alot of missing file informatin about objects.. It seems that I have no information about my own written rails-files.. I can see only infos about the lib-files. Have I something to do to give the file-infos to memprof?