Still this error when upgrading ("Conflicts: psa-mail-driver")

[King555]

I guess this is one of the most experienced issues when upgrading Plesk to any higher version since the release of Plesk 10. I got it with every single upgrade (but not with microupdates). The Plesk installer stops with this message:

E: Broken packages
—X— `apt-get` output ———————
Reading package lists…
Building dependency tree…
Reading state information…
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
plesk-mail-qc-driver: Conflicts: psa-mail-driver
psa-mail-qc-driver: Conflicts: psa-mail-driver

———————- `apt-get` output —X—
Collecting error details into log file…
Synchronizing the Debian APT package index files…

ERROR: Installation will not continue
Not all packages were installed.
Please, contact product technical support.

I know there is a solution for this (because there were so many people with this error and the error is there for such a long time). I always run this command:

apt-get install psa-mail-qc-driver

And then it works.

But the big question is: Why is this bug not fixed? Why do I need this step every and every time?

My operating system is Debian lenny 5 x64.