Alpha smoke video problems

What I’m trying to do is make some simple gun show smoke shown in the tutorial here http://www.youtube.com/watch?v=SsViAvVYoMQ at around 3:15. I found a video similar to the own he used in the tutorial and have attempted to achieve the same effect in blender but have had some problems. In the map input I enabled the 2nd alpha option (so it was yellow) and turn the alpha value all the way down to make the black background transparent, but keep the smoke visible. The problem (i think… I could be wrong here) is that the black in the video is not black but a tad lighter shade of black. That makes it so there is a MOSTLY transparent but not completely transparent plane, since that is what i’m using to play the smoke video on. Also this method make it so the smoke is so transparent that it is quite difficult to see.

Does anyone have a fix for this or any other method that would allow the black background to become fully transparent? I would also like to point out that the 2.5 smoke simulator is takes to much power from my computer and that way of creating smoke is out.

I’m using 2.49b, as 2.5 isn’t cooperating with my computer right now. :frowning:

Thanks for any help!

Anybody have anything to help?