The new version of libltdl is not binary compatible to the old one, which
will result in error messages like this:
tilman@brimstone [~] > mpg123
mpg123: error while loading shared libraries: libltdl.so.3:
cannot open shared object file: No such file or directory
tilman@brimstone [~] >
Just rebuild the application in question (in this case, mpg123) to fix
the problem.