To use the dynamic loading of behaviors, you need to set the following 
environment variable (in your .cshrc file for tcsh users, or the equivalent
for bash users):

setenv IVP_BEHAVIOR_DIRS '/home/bob/moos-ivp-extend/lib'

IVP_BEHAVIOR_DIRS=/home/bob/moos-ivp-extend/trunk/lib
export IVP_BEHAVIOR_DIRS