Anonymous Users and HTTP_X_FORWARDED_FOR

The problem

When using proxy-cache mechanisms like Varnish or SquidCache anonymous users get's the same ip.
By using the current

"function _vote_up_down_get_uid in vote_up_down.module"

will only allow one anonymous user to add vote.

The solution

The solution is to check that the variable

$_SERVER['HTTP_X_FORWARDED_FOR'] 

isset like they do in the

"function votinapi_add_vote in the votinapi.module"

.

Check attached file for a propose on a solution.