Pawet,
Im going to go in favor of silenceing the function for the time beeing, unless of course you know of another way to get the field values that Im after without the the current post id. The point of this functionality is to prevent people from saving duplicate venues of the same name. In future I'll be checking againts other fields as well, to further narrow down the results.
Two questions:
Where is types_render_field() found?
I've disabled the download link. Can this thread become public again? I'd like to save this thread in my comments for future devs to reference.