Is the poller creating a table? If so the polled data and alert may not play well together. This is an item I am investigating.
actually i just got off of the phone about 1,5hours ago...
apparently SolarWinds has a lot of problems with the "Test Alert".
For me I have never had any problems with it except now where it just wouldnt show the CustomPoller.Status when it was triggered by the test alert (it would trigger for some other custom interface poller instead).
It works well if triggered for real tho.