Disable drag and drop

Dropmark's Browser Extension has drag and drop detection. When you drag something on a webpage the Dropmark logo will appear on the right side of the browser, so you can easily drag items straight to Dropmark. 

However, if this is causing you headaches with drag and drop sites like Trello, you can disable the drag and drop detection. Start by going to the browser extension's Options menu. To get to the browser extension's options right click on the Dropmark icon in your browser and choose 'Options'. Once you have opened the settings, uncheck the box for 'Enable drag and drop detection'