Accessing 2 AuthUserFiles using htaccess?

[codemonkey]

Been racking my brains and googling for a couple of hours but so far i can't figure out how to do this.

I've got 2 htpasswd files on one server and I want to authenticate users against them. They have to be in 2 different files because one site that we have allows access to all our sites, which comes from a central location. The other file is for each individual site.

When I use this htaccess

AuthUserFile /path/to/htpasswd1
AuthUserFile /path/to/htpasswd2

It only authenticates users that are in htpasswd2 and ignores the htpasswd1 file

Anybody have any experience doing this and if so would they be kind enough to share

Thanks!