Why is it that the first time a CAnimateCtrl is displayed the frames are shown very slowly?

Hello,
I have a CAnimateCtrl in my dialog box, and i load a big and heavy AVI with it. The problem is that the first time (and only the first time) the AVI is displayed, the frames are shown SLOWLY - very slowly - about 3 frames per second!
If you have any idea what the problem is or have some sort of a solution - please post a response.

Thnx!
Ziv Ayalon