If you have a blank line of code before the download code that can cause the corruption. I'd need a copy of the page to track it down, but that is usually the issue when someone reports problems like this. The download code hasn't changed at all from Databridge v1 to v2 and it doesn't use MySQL code at all either, so that isn't the cause.
I'm guessing you have a blank line or other characters in the code on the page. If you want to give me FTP access I can help you track it down.