xf86-video-modesetting.tcz is still included in the 6.x x86 repo, see:
http://repo.tinycorelinux.net/6.x/x86/tcz/xf86-video-modesetting.tcz.infoPlease remove it! That separate extension is outdated.
xf86-video-modesetting is included in xorg-server since version 1.17.0.
The 6.x x86 repo does have version 1.17.1. The xf86-video-modesetting which is built into xorg-server will automatically being used if you do not install xf86-video-intel / xf86-video-ati / xf86-video-nouveau / xf86-video-fbdev / xf86-video-vesa and the likes.
Please remove the xf86-video-modesetting.tcz extension, to make sure that the xf86-video-modesetting which is built into xorg-server will be used.