In case you have upgraded your WebOffice 10.7 SP1 application, be sure to delete the browser cache of the browser you are testing with. Keep in mind that this setting only affects your local browser. Make sure your users are aware of cleaning their local browser cache as well. You could, e.g. send out an e-mail or provide an info screen in WebOffice with a description how to delete the browser cache.
See an example for such an info mail or screen:
WebOffice has been updated to the latest version! Please delete your browser cache to assure correct functionality. Consider the following steps:
Note: After clearing the browser cache close all browser windows and start the browser again!
Internet Explorer:
•Navigate to Tools menu and select Delete browsing history...
•It is sufficient to check the checkbox Temporary Internet files and website files. Be sure to uncheck Preserve Favorites website data.
•Press the Delete button

Firefox:
•Click the Firefox menu button
•browse to History and select Clear Recent History from the appearing menu
•In menu Clear All History select Everything as time range to clear and check the checkbox Cache
•By clicking Clear Now the browser cache is deleted

Chrome:
•Click the Customize and control Google Chrome button
•browse to History and select the Clear all browsing data... button
•In menu Clear browsing data select the beginning of time and check the checkbox Empty the cache
•By clicking the Clear browsing data... button the browser cache is deleted
