Version:           1.1.1 (using KDE KDE 3.0.3)
Installed from:    RedHat RPMs
OS:          Linux

If I double-click a class on a class diagram and try to add a new operation with a name that already exists (overloading), Umbrello says "The name you entered was not unique! Is this that you wanted?"

Answering "Yes" does add the operation to the tree list on the left, but it does NOT add it to the diagram. To add an overloaded operator to the diagram one must add it by right-clicking the class name in the tree view and then select "New" -> "Operation".

Occasionally I have been "able" to crash the program as well while adding overloaded operators, but the crashing has been too random to notice any pattern.