I am not sure if that is really the reason for the bug but..
I did a votetrade with geoffism

I took his ip from my list (excel) and put it in the browser.
I saw the website and voted but he didn't receive my votes.
EDIT: In other words: I wasted my votes.

I think the problem is that excel adds a [blank] char at the end of the string.

the browser doesnt concern about this char and finds the website but the vote can't find the player.

I dont know if that will prevent votes too if you put some parameters behind that ip...