Howdy - I recently upgraded to OS X Yosemite 10.10, and Firefox 32.0.3. Frequently, but without consistency, the upload file or attachment window will not disappear after I have selected a file. For example, in Wordpress, I will go to import a file to Media. I will select the file and try to add it. It will be added, but the window from which I made my file selection does not go away. It can't be moved, it can't be interacted with, I can't pull any other window on top of it. Or in an email, to add an attachment, I will select the file, press OK and the upload window will hang. This happens regularly, but not with any pattern or consistency. It seems to happen more if I press return to select a file versus clicking the OK button, though that is not a failsafe way of doing it. Would be thrilled to hear if anyone has a solution or a troubleshoot to this. Thanks for your help and best regards.