Motion tracking Sequence only render two frames

Hi, i searched the forum but i didn´t found an answer. I have a project with a sequence that contains one clip strip , one scene strip and one alpha under strip. When i start to render the animation, blender only renders correctly the first two frames, after this, continues rendering only the scene. I think i do all things well, so i hope it would be a Bug, but i´d like to know if anyone more have this problem. Thanks!

I think there is a bug in 2.49 where, if there is a scene strip loaded in the VSE, Blender will render only the scene strip.

maybe if i render the scene as video with alpha channel, and put it in the sequence editor can solve the problem, im going to test!.