From: DeskNow Knowledge Base
http://www.desknow.com/kb/

When I edit a new event, the date fields do not work properly, or I encounter other problems
http://www.desknow.com/kb/idx/5/201/article/

This may be caused by an antivirus, browser toolbar, etc. that is trying to prevent popups in your browser. Not all popup windows are bad.

Disable popup blocking in the antivirus/toolbar you're using (if enabled), clear the browser cache, and try again.