I wanted to copy some text in a mail using Ctrl+C and got the following error:

Ambiguous shortcut detected - Kontact

The message pointed me to 'Configure Shortcuts' under the 'Settings' menu to fix the ambiguity. Sure enough in shortcuts there are 2 'Ctrl+C' entries for Copy. Question is how do I remove one of them?

Anyone else seen this?

You simply need to replace one of the shortcuts with a different shortcut or select the "None" option. Clicking on a shortcut will display these options in that dialog.