My MacBook Pro (2007) on Lion has a strange behaviour.
Sometimes Chrome browser stops working. When I then launch Safari, it can not load any web page.
When I try to download a large file, it can be unresponsive.
Sometimes working with PDF files (even small files) has the same result
Sometimes I can not view files in my folders because Finder loads them very slow (it's showing spinner indicator).
I haven't found another way to resolve these situations besides restarting the laptop every time they happen.
What can be the issue? At first I thought about my HDD but my S.M.A.R.T. Status is Verified. Any additional ideas are highly appreciated!
Update : Activity Monitor shows