15
Sorry to doubt you on this, but I only ever develop with FF (version 3 exact)and use IE for testing purposes and I don't have problems viewing the image.
Lets test this right here :)
First one that you gave in your post:
http://www.xclusive-images.com/images/ FREE DOWNLOADS/BANNERS/BANNER4.jpg
Image:
http://www.xclusive-images.com/images/FREE DOWNLOADS/BANNERS/BANNER4.jpg
And the final one:
http://www.xclusive-images.com/images/FREE%20DOWNLOADS/BANNERS/BANNER4.jpg
And nice bug catch on the last one ;)
Will add this to the bug tracker and get a fix.