capturing frames matters

[medialover]

i have 3 matters.

1. why is there not difference when capturing "original" or "what you see"
(P , Shift+P) the images are exactly the same.
i want them to be saved in fullscreen size

2. why is there a stop when using frame by frame? it allows only 5 minutes segment then i have to unactivate the pause and forward the movie to continue.

3. I noticed when i use frame by frame for 4-5 minutes the pictures captured then have gfx error, why?

thanks