I'm using the demo space.
On the first page I click on edit. Then go to Rich Text view then back to Wiki Markup.

The problem:
Each time I do this the wiki markup shows more px's at the Image macros:

[!_Images^btn_examples.png|width=220pxpxpxpxpxpxpxpx!|Examples]
[!_Images^btn_examples.png|width=220pxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpx!|Examples]
[!_Images^btn_tutorial.png|width=220pxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpxpx!|Tutorial]

It may be an issue with Firefox 3.6 , I don't see the issue with IE.