Package Updates on Debian

I have the etch-backports repo in my sources.list.
That repo has some packages with higher versions than the installed ones, but lower priority, so apt-get upgrade totally ignores them.
I don't know what Virtualmin does exaclty to determine which packages need to be updated, but it ignores the fact that those packages have lower prioirity than the installed ones, and offers me to upgrade my mysql server, postfix and spamassassin among others, which I don't want.
I think this behavior should be changed.

Status: 
Closed (fixed)