Problems with the screen when I plug the charger

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http://askubuntu.com – I installed ubuntu 12.04 LTS a few days ago. Frisrt I had a problem whith the screen, I explain myself: When I shifted between windows or I moved up and down through a website, the screen seemedd to have like stripes, and for two or three seconds or so it doesn't work. The other day I succeed in fixing it, but only when I'm using the batery. Whenever I plug the charger, the problem appears again. It happens whe I take out the batery and plug the charger, and also when I've been using the batery, and I plug the charger. I don't really know what to do. My laptop is a Toshiba Satellite L850-150 a (HowTos)