How can I reset ObjectDock to the default settings?

First you will want to back up any dock settings you may have if you wish to keep them.

To get back to the default settings, go to:

Settings -> Troubleshooting Options, then click 'Reset ObjectDock's general program settings' and 'Reset the contents of my docks'.

If you were having issues with the dock with your prior configuration, try running the dock in its default configuration before restoring your settings to see if your issue persists.