I ran memtest and got 1000's of errors. I have 2 sticks of Patriot G-series 2gb PC2-6400 ddr2-800mhz ram. I switched them out and discovered only one was giveing me errors. When I tested the bad one alone I got over 1000 errors in less than 30 secs. My computer seems to run ok with them both in, and its displaying 4gb of memory. Do I need to immediately remove and replace the bad stick or is it ok to keep useing it?