It may be flash maybe. Something I am seeing it using over 100,000K. Especially, when it makes firefox and/or the computer freeze. Less than 5 tabs, it is around 300,000K; but over 5, it tends to go up to 500,000K.
As long as, it doesn't freeze; there is no problem, but when it freezes the computer, that is bad.
Thanks for your help.