PHP extension upload progress - returning negative total bytes and time remaining

I'm using the PHP upload progress extension to retrieve information about files being uploaded to my web system. However for files larger than 2GB the total bytes and time remaining fields are being returned as negative numbers.

Refresh progress bar in notification bar

I would like to put a progress bar in the notification bar. The idea is showing the progress bar while the program uploads a file to a server. Everything else is ok, but I can not figure out how to refresh the progress bar inside the notification. Does anybody knows any pattern to play with? I mean, where I should refresh the progress bar, in a service or activity and so.