I would drop back a little bit and reconsider the package manager you are using. It may or may not be related to your immediate problem, but Synaptic merely adds a level of complexity to package management that, as a Slackware user, you do not need.
I have never liked the apt-get -f option either. It often works to clear up such problems, but, IMO, it is clearing a symptom of deeper problems, rather than solving them. Back in the day when I used apt-get, I would have first attacked such an error by using, "# dpkg --purge slapd", then attempting a reinstall.
Beginning with Etch, the Debian recommended package manager is "aptitude", and again, I recommend it's usage as a command line instruction, rather than the ncurses interface generated by # aptitude without any parameters. The reason it has become the recommended package manager is that it supposedly handles dependencies in a fashion superior to apt-get. The apt-get program in Sid attempts to mirror aptitude's dependency handling, but I have heard that it is still rather buggy.
A warning: Aptitude still does not always play nicely with packages that were originally installed with apt-get, dpkg, or manual compilation. A good precaution is to first execute, "# aptitude keep-all"
Finally, don't forget that you are using Sid, and dependency issues do occasionally arise there.
Last edited by rickh; 08-13-2007 at 10:25 AM.