fishypost detection should only log when a post comes from a different host name than the one the site is running on (ie if the url referrer does not match the current site host name), it should not happen when doing anything directly with the site ui. maybe you have a proxy server or something like that which could make it have false detection of fishyposts. you can disable fishypost detection by adding this in user.config:
<add key="CheckFishyReferer" value="false"/>