Hi Terry,
You're right. Our version was one year old. I downloaded the last one and the EMPTY alert has disappeared, many thanks.
The "double browse button" issue is not completely resolved, but it's much better now. Actually, we use the AjaxUploader inside a grid (a control we developped ourselves). And we get the "double browse button" only after a postback, for existing rows. But I'd say it's ok like that.