Help with Inserting Images

Hi,

This could very well be a stupid question, but whenever I try to insert an images to a mod page, it always appears as the broken image icon.

I've copy and pasted from local files, copied urls and inserted using "image" button, uploaded images to seperate sites and copied urls there, but it always just results in the same broken image icon. It works occasionally in the preview window, but then I click the save changes button for the mod description and it says that there are words that break the websites rules. Even when the image is titled test.

Thanks,