I write this tutorial to explain how I solved the problem of slow downloading and bad performance with Download Station regarding emule with my DS209j.
- stop the download station service (disable "enable eMule downloads")
- enable ssh or telnet and login as root (same password as admin)
- edit amule.conf file with the following command:
vi /usr/syno/etc/amule/amule.conf
- scroll to the line that indicates "ConnectToKad=1" and modify it to "ConnectToKad=0"
- save the file and re-enable emule downloads
OPTIONAL: you may also lower max active connections from 500 to 300 in emule preferences tab

