Incorrect window matching

[junkie]

If you use Evolution in express mode (evolution --express), you get nice, separate windows for each module (Mail, Contacts, Calendar, etc.). Docky can't handle this, not even with StartupWMClass in the .desktop file. I have three .desktop launchers pinned to Docky (mail, contacts, calendar), but every additional component launch produces another running indicator dot under the icon of the first launched module.

For example:

1. I click on the Mail application icon, the Mail application starts, one running indicator dot show up under the icon.
2. After that, I click on the Calendar application icon, the Mail application window pops into focus, and the Calendar application starts. A second running indicator dot appears under the Mail icon. No running indicator dot under the Calendar icon.
3. I cannot switch between the two windows, because clicking the Mail icon focuses both windows, and clicking the Calendar icon launches a new instance of the Calendar application.

Relevant part of the .desktop file:

E.g. Calendar application:

Exec=evolution -c calendar --express --class=evolutioncalendar
StartupWMClass=evolutioncalendar

I double checked, the window class (--class=evolutioncalendar) gets set perfectly on the window, but Docky doesn't seem to make use of it, it just groups by executable name, which is of course "evolution" in all instances.

OS: Ubuntu 11.04
GNOME: 2.32.1
Docky: Docky 2.2.0 bzr docky r1830 ppa