Which one of those products has no image assigned to it?
Remove the image for one of those products and then have a look. You'll see that it will pickup the image from the previous product.
You have $catimage nested inside a while statement:
while ( $row = mysql_fetch_row($queryv) ) {
If you stick it inside an if statement, such as "if ( file_exists($checklink) ) {" and there's no image, $catimage retains the value from the first iteration and displays that.