You should rename your file field to match what you are using in the InsertSB, or update the InsertSB...
The browse is hidden at first because it is dynamically positioned based on the size of the image added (if any). It should be hidden at first, but javascript should run to position it and then display it. It is hidden at first so that you don't see it jump as the page loads and the script runs. If it doesn't show, then the javascript isn't running properly.
If you can put up a sample page where I can look at it I can debug and let you know why it isn't showing.
Did this help? Tips are appreciated...
