Me testing your image...
OK, it looks like the IMG tag has to end with .jpg or .gif, or whatever your picture's extension is. It can't end with the ?imgmax=512 part. Second problem is that once you remove the ?imgmax=512, then the pic is too large. Try downloading the pic, sizing it smaller, and then upload it to imageshack to host it. Post it with [IMG] imageshack address [/IMG] and you should be OK