How to control autogenerated custom dependencies ?

EUDC consists of eudc.el for the front-end and eudc-ph, eudc-ldap and eudc-bbdb for the three supported backends. I would like the system to load only the front-end and the necessary backend files according to the protocols the user actually wants to use. The problem is I use custom and made eudc-ph, eudc-ldap and eudc-bbdb be subgroups of the larger custom group eudc. Therefore the generated custom-load file includes: (custom-add-loads 'eudc '("eudc-bbdb" "eudc-ldap" "eudc-ph" "eudc")) which means that whenever I load eudc all the backends are loaded. I really need to avoid this. What should I do ? Oscar