Upon loading mod_nibblebill I get the following
2009-02-05 12:49:42 [CRIT] mod_nibblebill.c:242 load_config() ODBC does not appear to be installed in the core. You need to run ./configure --enable-core-odbc-support
mod_lcr and mod_easyroute which also use ODBC are loaded and report no problems. Everything related to the ODBC connection is identical in autoload_configs/conf/nibblebill.conf as in lcr.conf and easyroute.conf.