I just installed my new hd4850 palit radeon card when I boot it up horizontal red lines come across the screen(even in bios)they are not static and sometimes dots appear all over the screen too.. i reinstall my old card and all is fine again??anyone have any ideas as to what this could mean.. Oh as a side note my power supply "750w" really 500w has two 6-pin pci-e connectors the card has an 8-pin but came with a 6-8 converter and thats what im using