Problem of adding an image

When I add an image with the button of the image's link,two of the same image will be shown.And if I upload an image from my harddisk with the components of "Persits Aspupload",only a icon of the image shows to me.But when I upload other types of files rather than the images,it's ok.Why? And how can I solve the problem? With you please help me about that? Thanks.

  P.S.

I found the same problem of the twin images in your forum,so before I post the message,I should delete one.Is that the bug of the forum?

Thanks for your answer.

My IE is 6.0+sp1.

I had compared the forum 7.01 with 7.5(full).It's OK to link or upload images in 7.01,and usually errors occurs with 7.5.May be it is the problem of the new version.