I'll check what you said, maybe there is something I can't think of right now.
The only thing that comes in mind is that I don't draw a specific area of the map size on the board. I draw all 1000 tiles, even though those that are not supposed to be drawn. Is it possible that causing the issue? In other words I am NOT implementing something like this: http://user-generated-content.java-gaming.org/img-vault/d7729d02ad9f36f000dfbbec5d2a51d10d7bde17a12ded3b82ec52acbd79de60.png . Instead all of my tiles are drawn.