FreeBSD's ldconfig binary doesn't work the same as the one in Linux derivatives. If you happen to type ldconfig -v, for instance, you're going to lose all your configuration information. To fix the problem:

# ldconfig -m /usr/local/lib/compat/pkg                                                          
# ldconfig -m /usr/libexec                                                                       
# ldconfig -m /usr/X11R6/lib                                                                     
# ldconfig -m /usr/local/lib                                                                     
# ldconfig -m /usr/lib

Given an executable /path/to/EXEC:

$ ldd /path/to/EXEC