What's up with the -domain stuff? I think that could be your problem. Try removing it or replacing it with something static. Also, check that the clock on your webserver isn't more than 8h off (I've seen it happen!) since you're setting a pretty short expiration.

Are you sure you don't have a cgiapp_init() defined in one of your sub-classes? Maybe add a warn() in the super class one and see that it actually prints when you run both sub-classes.

-sam