I just noticed that the Labs section of GWT is showing Instant Previews. When i compare my site to the instant preview google is showing 35 errors but the instant preview is working fine.
these are the errors shown
.css, .js, gif & .jpg are 'Roboted' (what ever that means)
other .jpg have a Fetch Failure
but as i said the Instant Preview is working fine in GWT and in the SERPs. very odd