I've come across a problem with the latest Mesa CVS commit to
r300_state.c, described as "fix broken write-only depth setting. use
early z where possible."

When using Scorched3D [http://www.scorched3d.co.uk], the top half of
the 3D vehicle models seems to get chopped off, and the camera views no
longer work.  I can't describe it very well, so I've linked to some
screenshots:

Mesa CVS using revision 1.163
of /Mesa/src/mesa/drivers/dri/r300/r300_state.c
http://sturmartillerie.org/linux/mesa/scorched3d_01.png
http://sturmartillerie.org/linux/mesa/scorched3d_02.png

Compare these to screenshots using the previous version:

Mesa CVS using revision 1.162
of /Mesa/src/mesa/drivers/dri/r300/r300_state.c
http://sturmartillerie.org/linux/mesa/scorched3d_03.png
http://sturmartillerie.org/linux/mesa/scorched3d_04.png

As you can see, something is amiss here.  The version numbers given
above are from the CVS tree, but I'm actually using the freedesktop.org
Mesa CVS git mirror:

http://gitweb.freedesktop.org/?p=users/krh/mesa.git;a=summary

If I use your commit tree [13b4d44d75f3d92be459782e57e81bcff900aa8b],
Mesa is broken, but if I use the previous tree
[f2b7907cd5fd7a7b295e2c43204b993336f498ce], all is well.

If you need any more information, please let me know.

Here are my computer specifications:
CPU: AMD Geode NX 1750 1.4 GHz, Motherboard: iBASE MB740 Mini-ITX,
Memory: 1GB PC2700 DDR, VGA: ATi Mobility Radeon M10 9600 AGP, OS: 2.6.18-rc4, 
Gentoo 2006.0, X.Org 7.1.1.