When using the CSV importer, it has a tendency to open modal windows behind the CSV importer window, which makes KMyMoney appear to have locked up. You can't even move the window that's blocking the new dialogue, because the new dialogue is modal. I've noticed this on warning messages, as well as on selecting the account to import into at the end of the process. Here's one way to reproduce it:

1) Open a KMyMoney file with a CSV banking profile already set up.
2) File -> Import -> CSV
3) Select an existing CSV profile
4) Click the 'clear' button to the right of the profile name.
5) KMyMoney will pop up a modal 'Delete or Edit Profile Name' dialogue UNDER the "CSVWizard" window to which it's parented.

Workarounds:

1) Make sure you move the CSVWizard window AWAY from the centre of the screen before doing anything with it, so it won't be blocking any windows that pop up.
2) On Windows, you can use Alt+Space,M to enter 'move window' mode. Use the cursor keys to move the window out into the open.

The core of the problem seems to be that the CSVWizard window is a topmost window, staying on top even when other applications are open.