Is my G5 destroying my RAM?

A few days ago, my Power Mac G5 would not start - all I got was three flashing lights. A quick look online told me that three flashing lights meant some of the RAM was bad. After a little investigating, I took out the bad pair of chips, and the computer worked great.

Within a day, three flashing lights. I took out another set of RAM, and fired up the computer. Worked great.

Now it is the next day, and once again, I have the three flashing lights.

Is my G5 destroying my RAM? I have no more to try. Thoughts?

Thanks for any insights.