We have a problem that occurs only with Firefox and UploadType set to IFrame:
in this case, when clicking the "browse" button of the UploadAttachments control, then a control similar to the html upload control is displayed. And we have to click the "browse" button of that control in order to popup the dialog in which a file can be selected.
With IE or with UploadType set to Flash, we don't have this problem: clicking the UploadAttachments browse button directly open the select file dialog...
Any idea why we get this problem?