There is a long living bug in your board software with the "Preview Post" button. If you use it without adding a picture link, you will see a preview of the text as expected. But if you use the "Post Message" button from the preview, all you get is this error message: > Form validation error > Only .GIF, .JPG, .PNG or .TXT files can be uploaded > Please press Back, correct the errors, and try again. I would guess that the software checks for the picture name extension but fails to handle messages without pictures at all. We can live with this (the workaround is to use the browser "back" button and post from the previous page), but I think it would be better to either repair the button, or just to delete the button - having a button which creates nothing but the error message is not that useful... :-)