In the meanwhile (KDE 4.3) the software was improved and with some manipulations konsole can be forced to start with a fixed size.
Start a konsole session:
Open the menu by clicking on the upperleft icon, choose Advanced, then Special Application Settings:
In the Settings window go to the Geometry tab:
Select the following options:
- Size -> Apply Initially, input your preferred window size
- Maximized horizontally -> Apply Initially
- Maximized vertically -> Apply Initially
Make sure that the two checkboxes after "Maximized horizontally" and "Maximized vertically" are not selected, else the "maximize" setting will maximize the window on every start.
Save the settings by clicking "OK". That's it. Now every new konsole window should start with a fixed size.
Now if the KDE team could fix this other outstanding bug too: The session manager does not store the encoding when KDE is shutting down. Every window is opened again after the restart, but each window has the default encoding. Very annoying, if you have to work with different encodings on remote machines.