Memory issue on ML

I'm having this same problem. It just started today out of nowhere.

I've had ML installed for a couple days now. I hadn't restarted in a few days so I restarted my computer an after that, this started.

I found that you can go to TERMINAL and use the command purge to clear that inactive memory.

But thats only a temporary solution.

Yeah, after purging twice, mine seems to have leveled out back to normal.