Hello jocreatons -
different browsers support the drag and drop capacity differently, so it may be that the browser you are using does not support that feature as well as other browsers, or there could be an issue with the steps you take to do so. If this difficulty persists for you, please feel free to file a support case from under the Help tab of your account and be sure to include your browser and operating system information in the case so we can take a look.
- Craig