I have created a Google Maps mashup for a local non-profit, allowing users to contribute markers/points of interest with a description and attach images and mp3 files. It works great but I have one little niggle that I'd like to get worked out before I release it to them.

You can see the map at: Interactive map of the Severn estuary - Tidal Severn

Log in (top right) with sitepoint/123 to submit a marker. You edit existing markers through the My Account tab. It should be fairly self-explanatory.

If you click the New Marker button, it will drop a new marker in the centre of the map. Move it, and it will open an InfoWindow with options for saving it. There is a SELECT FILES button (jQuery's Uploadify plugin) for uploading images and mp3s. This works fine in IE, Chrome and Opera.

However, in Safari the button is shifted to the left and can't be clicked. In Firefox it can be clicked but it is invisible.

Removing my CSS doesn't fix it. I really have no idea what is causing it or how I troubleshoot it.

Any help would be greatly appreciated.