[Plugin: WP-DownloadManager] Download File size limit

Hi

I installed this plugin in my blog and it works fine, but there is a problem when the file exceed 1 or 2 MB.
Example: on of the files is 43MB. Tried several times and downloading stops at 13MB.

Is it a limit in wordpress, Download Manager or the server?

Regards
Guillermo

http://wordpress.org/extend/plugins/wp-downloadmanager/