Hmmm... can't say I've seen that before. I agree that 4gb of RAM should be more than enough for Firefox. Chromium has a history of fetching and installing binary blobs w/o asking for user permission.

I'm curious about the frame skipping is caused by -- I've never seen that problem. I'm wondering if maybe it's video card related? Might be worth asking someone involved in the project about to see if it's a known issue.