http://ports.haiku-files.org/ticket/401

There is a bug in the SDL Haiku port, which shows up in TuxPaint and perhaps other SDL apps/games built for Haiku using custom cursors.  The task will require you to track done what's casuing the bug and to fix it.  You'll need to have a wokring install of Haiku and HaikuPorter.  With HaikuPorter you can build SDL from the mercurial reposity using "haikuporter -i libsdl-1.2-hg".

To build tuxpaint for testing out your fix, you can also use haikuporter.