desktop icons

WinXP Pro
Last a few days, when I turn the computer on, when it boots up to desktop, it moves all my icons on my right monitor to the left monitor. Then I have to drag them back to the right monitor. Each time when I turn the power off and on, all icons on the right monitor moves back to the left screen(monitor).
I use dual monitors with one graphics card with two connectors. It just widens my screen. I have tried all desktop settings etc. but no help. I would appreciate any recommendations. thank you