Demonoid ratios are notoriously inaccurate.  Unlike other 'proper' private trackers they don't use any keys in the announces or torrents but instead rely on IP addresses.  This fails on many levels.

Anyone with a dynamic IP address is pretty much guaranteed to have an incorrect ratio.  Demonoid simply use the address you had when you last logged in there, so if your address changes then it won't be connected to your account or the torrents you're running.  Further, if someone else is allocated your IP address as last recorded by Demonoid then all their transfers will be assigned to you.

And it doesn't work at all if you use a seedbox.