Hi
I followed the link but you have a spelling error on the website from the download so the link doesnt work.
ftp://ftp.dlink.eu/Products/dir/dir-850l/dirver_software/DIR-850L_fw_revA1_1-07b01_all_en_20130621.zip
If you correct it manually it can be downloaded.
I hope it fixes my issues with random internet disconnects that i have since i installed the 850L.
Speed is great though but my former router the TP-Link TL-WR1043N had no issue what so ever with internet disconnects and it is almost the same config. It seems to run fine for hours and then it disconnects and i have to reboot the router, release/renew IP or deactivate/activate the network adapter then it works fine for the next few hours. Lets see if something changes!