ICE-Q fan in reverse?!?

[stiby]

After purchasing a new graphics card to my surprise I found I was sent the wrong card. The card I was sent came with a hugh heat sink which should suck the air from the case across the heat sink and out the back (Excalibur 9800Pro IceQ).

Upon using the system I find that the air dosn't seem to be expelled out the back but sucked into the case and out from the fan.

Is there a way to easily determin this basic investigation is correct and if so is it safe for the fan's power to be reveresed?

FYI...
Just been told that a simple but effective test of airflow on such a small scale would be to use a match. Blowing out the match will generate smoke which if the fan is working should be sucked in and out the back.