OK, I've figured out the problem, but not the solution and could use some help. The problem, incidentally is with the alert rule and not the poller itself - the poller is working fine it turns out.
So, we are trying to say if the value of the poller is over 90%, trigger an action; however, the poller returns an entire table, so that just doesn't work. What we need to find out is how to say if any of the values in column x is over 90%, trigger the action.
Any idea how to do that? Thanks