I've had this computer for over a year, and suddenly my computer screen filled with weird pixel-ish looking rectangles, and it told me to turn off my computer. when i turned it on again the screen went grey and bizarre. I restarted again, and it sent a panic warning to apple. It said something about a kernal warning. It started to happen again today, and i restarted just after it froze, and before the rectangles haunted my screen again. coincidentally my battery was having a lot of problems, and i just put in a new one (after all of this happened). Is it possible it was just my malfunctioning battery, or is there something i can do to check, so that this doesn't happen again?