FOSS gamedev and creative worlds

I run a 1gb ram netbook (Pathetic, I know) with windows 7 (starter), and Minetest is running INCREDIBLY slowly recently (only since yesterday) at about 15-10 fps, sometimes dropping below 9, at which point I turn off my computer and play Xbox. It has never done this before, and it usually runs at about 30fps, 60 on a very good day. Can someone help? It doesn't seem to be affected by other applications running, because once I was amazed to find my brother playing on 30fps, with chrome and several notepad windows open. Help?

Version?

DO:
- Set disable visual themes to true under compatibility
minetest.conf:
- Set fullscreen = true
- Set wanted_fps = 30

if its the new version im having the same issue with low running speed 0.4.1 was good but 0.4.3 has some lag issues

No, I am running 0.4.2 at the moment.