Visible Seams in Lightmaps

Hi,

Maybe someone can help me with my issue,

I'm making a cylindrical object

Here it is in 3dsmax : http://img4.hostingpics.net/pics/2068353dsmaxMesh.jpg

here are my UV2: http://img4.hostingpics.net/pics/764734UV2.jpg

The problem is the result with unity when my lightmaps are baked :

Here are my scene lightmap parameters : http://img4.hostingpics.net/pics/562774params.jpg

and the lightmap itself : http://img4.hostingpics.net/pics/732529lightmap.jpg

I've tried a lot of t$$anonymous$$ngs, increasing the padding, the resolution and changing General Gi to HighResolution, and also change the Object scale in lightmap to 15, not$$anonymous$$ng worked The only t$$anonymous$$ng that make t$$anonymous$$s seam disappear (but still a bit visible) is to enable the final gather.

Is someone have an answer why t$$anonymous$$s happened and maybe how to avoid it on cylindrical objects ?

Thank you for your time