Problem:Row Versioning with multiple field Primary Key

Hi,
I use postgresql 7.0.2 with ODBC 7.1.0003 as backend and MsAccess97 as frontend.
In order to be able to work with float and numeric values I must enable Row Versioning, but this only works with single field primary keys.
In my database design I use multiple field primary keys and also multiple field foreign keys.
For enabling Row Versioning I changed the multiple field Primary keys to a *dummy* single field primary key and created unique indexes but how can I realize referential integrity on these unique indexes???????????
I can imagine to handle referential integrity with triggers. Is there another, better solution for this problem?

Please, let me know where I can find some hints :-)
Kind regards
Irina

E-Mail: i(dot)hasenoehrl(at)aon(dot)at