Files over 15MB should be downloaded from web server directly, so it's not causing any load on our servers.
i wasn't aware of that, mucho thanks. just checked with network log, opera mini connects directly to the file source and so does uc mini. one wonders how they achieve the claimed download speed gains via my 32 kbit/s connection.
still, i'll continue to use their downloader as from past experience it seemed more resilient.
many thanks again for the clarification.