The title says it all really. I'm using ubuntu 9.04.
I've tried 6 players, and am just getting part of the image filling screen.
Is it screen resolution, and if so..?

What is the resolution of the video and the display you are trying to view it on? It seems pretty unlikely that the resolution of the video could be higher than the display on any modern machine, even if the video was in 1080p (which would be epic home movies).

I don't know where to find this info,
(don't know how you folks remember all these commands - from where I am it seems like a thousand random sequences to memorise, but it's obviously a language in which one can make intelligent guesses at commands for this and that, but not me, not yet, I aint no IT brain, just despise wndoze lol)
the camera is old enough to have been bragging about 3.2 megapixel, and the laptop is a D600 Dell, 7 years? old.
Ubuntu seems to lack a Control Centre place.

If it's not resolution issue, what then? These files played ok in wndze, although their native player couldnt even open them last time I was there

video is 320x640,screen is 1024x680

Which video players you tried? Don't know much about other players, but I know for sure, MPlayer have good function - mouses left button click and choose Half Size.
Xine have similar option.
Have You tried this? it may help

I,ve tried 4 or 5, but haven't seen that option, but i sure will when i get back to an electrity supply..