Bug in clearing cache (in pollfield_clear)

If you are having problems having your votes show up in pollfield, it's probably a cache issue. The problem, which I think was closed earlier though no fix was confirmed, is that the cache ID generated is wrong due to a typo.

Line 812, currently:
$cid = 'content:'. $node->nid .':'. $node->nid;

ought to be:
$cid = 'content:'. $node->nid .':'. $node->vid;

Changing this fixes the display problem.

I marked the issue as critical because there was no other category above 'normal', yet this issue affects all 5.x sites with caching turned on. Nonetheless it's a simple fix.