after attaching video file attachment list disapears from the form (when there is already a video file)

When I create content and upload video file (flashvideo field) first time it works fine. but when i update content and upload new video file. the attachment list and upload button disapears from the form. anyway if i submit the form ,newly uploaded file gets uploaded. i think flashvideo module does not allow upload.js to work correctly. as I get data in upload.module that is passed to upload.js. but can not be displayed on form. please help me to resolve this issue. you can seed the screenshot after i click upload button to upload selected file.