| so maybe the graphics isolates it's own little chunk of ram for itself? |
Yes it does. 64 Mbs of it.
Integrated graphics always takes some of main memory for itself, 32,64,128 or 256 Mbs depending on what the manufacture designed into the system.
If the is a desktop, installing a separate video card with its own memory will release this RAM back to the main pool If it is a laptop than you are stuck with it.