This thread also talks about the D-Bus message. I still can't think of what the culprit might be.

Please try the following: Start gPodder _without_ the "--maemo" switch from an xterm (or via ssh), i.e.:

This will not load all the Maemo-specific code tweaks (and it will look ugly, because it's not the Hildonized UI). When this gPodder is running, try to slide the keyboard open and see if it crashes. If it doesn't, we know that the problem is with the maemo-specific code

After closing this Non-Hildonized gPodder process, you can rm -rf ~/gpodder-downloads (the "gpodder-downloads" folder in your home directory) and ~/.config/gpodder (the "gpodder" folder in the hidden folder ".config" in your home directory), because they are only relevant for the Desktop version and will be created when running gPodder like above (without the --maemo switch).

Pleas try that and tell me if this makes any difference when sliding out the keyboard.