Tiny Icons On Xwindows Dock

[riow]

I've just tried it. How I found that some icons becomes very tiny abnormally after dragging the program shortcuts from desktop on Windows 7. For example, Google Earth and XnView become tiny, and some program shortcuts with customized icons become tiny. Some icons are normal such as Google Chrome, or Skype. Please help me to make them normal in size visually. The screenshot of XWindows Dock is attached.