Sorry I didn't grab either a save or screenshot :(

Using 3.13 patch (installing 3.17 hangs indefinitely for me :(), my caravel could see a work boat belonging to Genghis Khan, but this did not put our civs into contact.

a save would be good - as for the new patch: the autoupdater is buggy - download it from this site and install it outside the game :)

The work boat has to see you and if I'm correct caravels have a longer line of sight than workboats. So if, it's at the edge of the caravels line of sight, that means the workboat can't see you, hence no contact.

The work boat has to see you and if I'm correct caravels have a longer line of sight than workboats. So if, it's at the edge of the caravels line of sight, that means the workboat can't see you, hence no contact.

Indeed, had the same exact thing happen again. This time on the IBT, the wb moved towards me, and that caused contact.

It happened a similar thing to me..... ( do not open spoiler or save if you're planning to play the current LHC ... contains spoiler info ):
http://i184.photobucket.com/albums/x257/r_rolo1/LHC%20XXIII/Civ4ScreenShot0001.jpg