I'm having problems editing a filmstrip format in Photoshops CS4. I use After Effects CS4 to export a 5 second video as a filmstrip format. Then I'm opening that filmstrip format in Photoshop CS4. Every time a adjust two or more frames and then click, "save" Photoshop gives the following error message, "This image is no longer a valid filmstrip. (the image size or number of channels have been altered) It cannot be saved in filmstrip format." Once you get that error message, your filmstrip file is deleted. it disappears and you can't re-save it. That same error message continues to reappear.