Graphics issue question

I have a late 2011 MBP with ML.

I often see weird graphics 'see through' images. For example, if I have Safari open and then swap to Mail, I will often see part of a Safari image inside a link in mail.
I also had issues with my 24-inch ACD flickering black and showing a scattered desktop at time (but no longer have that display).

Is this a graphics card (or whatever it is called) issue or an OS issue? Or something different?

Is there a way to test the graphics card, and if so, how?

Thanks for any help.

-MS

 

Attached is a screenshot of an example of the graphics issue I am repeatedly seeing. This is a screenshot of part of an email as it appears in Mail. Any ideas what the red mess is, and what is causing it? It is supposed to be a hyperlink.

Thanks for any help.