I don't know what program you would need to use, as MJPEG is rare. Search around at some Matrox sites, such as www.matroxusers.com, and see if they have any utilities that you could use for the file convert, as the popular Rainbow Runner Series of capture cards (Matrox compainon board) also uses MJPEG
It's all in the codec. Try using a good MJPEG codec. www.jpg.com has one for download. Use it in conjunction with the divx or any other MPEG type codec. This should work on almost ANY video editing software. I really like virtual dub as a video editing solution. With the codecs installed on your system, you can directly copy from MJPG to DIVX or to any thing else. I don't know how this works with the MJPG format that Pinnacle uses, but I think it will work.