Pixel Art Distortion

I’m following the Game Tutorial posted by Marz, here:
http://www.kirupaforum.com/forums/showpost.php?p=337912&postcount=9

I cut the pixel guy up in different GIF and imported it into Flash. Trouble is, the little guy distorts whenever I run the movie (he looks fine on the edit stage though), like this:

I´ve tried all the different type of image properties, placed him on a whole number coordinate (like X30, Y20), used the break apart tool, but nothing solves it.

Should I be using PNG’s instead?

Thanks!!