Q: isight problem

Hi Folks

I got my daughter a old external isight cam as her built in isight on macbook pro 2009 is very blurry and has lighting background problems.

Anyway i tested the external on my late 2011, and awaked it over on edit menu on facetime to see if it would work. Great the external worked fine on the 2011 macbook. However when i tried the same on my daughters it was so slow that the picture just freezes, and maybe moves every 2 minutes. Colour not the same either.

Any ideas anybody, or is this cam no good with 2009, version, or any ideas how i could get the internal one working better?

Kind Regards

G