As part of upgrading from Debian Lenny to Squeeze, I also upgraded from KDE-Trinity 3.5.12 (Lenny version) to 3.5.13 (Squeeze version). After the upgrade finished, I tried to open Konqueror; the result was a hung machine.
when you upgraded within TDE, than the upgrade was not complete. redo the upgrade from a text console (<ctrl>+<alt>+<f1>).