your 300watt is probably a generic brand PSU. i would buy a quality 400 watt or greater for your system. low quality power supply will damage components when they fail. it's worth spending $60 to protect your investment. your 300 watt is probably straining under all that load, especially with your 9600.
some good brands i can recommend is enlight 420watt, enermax, and antec brand except their 430watt True Power model. best way to find a good product is go to www.newegg.com
and search under their power supply category. browse for items and click the "customer review" link. you can read reviews from customers who bought that product. i read both good and bad, but tend to read the bad reviews for warnings from product defects.