Sudden Blank Screen on Laptop

I have a toshiba a215. I was having problems with the screen blanking especially when I would run my zune software. I first thought it was that until I realized that it was just the display that was effected. I then when onto ati web site and downloaded new drivers for the 1200. When the blanking was happening it was everytime that i loaded that particular software because it really loads my cpu. After I did the update it went away for about a month and now it is back again. It has done it twice again within the last couple of days. I have sleep mode enabled on my computer but hibernation is no longer an option due to some changes that i made. with sleep though it should come back to life with closing and opening of the lid but it doesn't. I saw on some other discussion about changing the power management setting. They said change the setting min performance to 100%. I noticed that when on battery it was 5% depending on the power option that i had it on ie high performance, power saver, balanced. I changed the high performance setting to be 100% but set the others at 20 and 50%. the higher you set them the more power they will draw and you will run your battery down real fast. I will try this out for a little while and see what it does. try to pay attention to if this problem happens while plugged in or on battery. your power setting will change for your cpu based on those settings. if anyone has anymore suggestion let me know.