I installed apache from slink on Sunday, and the package apache_1.3.3-6 seems to require apache-common_1.3.4, rather than 1.3.3. It's easy to find -- but it's in potato, not in slink. It's probably just a typo which has slipped into the .deb, rather than an actual dependency on version 1.3.4. Perhaps someone else can check this, too.