I'd like my task bar to show only those apps started on the current desktop.

let me explain.
If I am on desktop #1 and open a konsole window, I see that konsole in the taskbar.
Now I switch to desktop #2, but the taskbar still shows that konsole in the taskbar. I want desktop #2 taskbar to be empty until I open something there.

If I then switch back to desktop #1, I would again see the konsole.

Hope this explains what I'd like. Is this possible?

I am using KDE 4.3.5 release 0.

Thanks

task manager settings -> general -> filters -> only show tasks from current desktop

why are you still running 4.3.5? that is very long in the tooth