diff -up Mesa-8.0.1/src/mesa/state_tracker/st_manager.c.jx Mesa-8.0.1/src/mesa/state_tracker/st_manager.c
--- Mesa-8.0.1/src/mesa/state_tracker/st_manager.c.jx	2012-02-14 18:44:00.000000000 -0500
+++ Mesa-8.0.1/src/mesa/state_tracker/st_manager.c	2012-04-02 12:02:14.613964417 -0400
@@ -528,6 +528,9 @@ st_context_teximage(struct st_context_if
       if (util_format_get_component_bits(internal_format,
                UTIL_FORMAT_COLORSPACE_RGB, 3) > 0)
          internalFormat = GL_RGBA;
+      else if (util_format_get_component_bits(internal_format,
+                 UTIL_FORMAT_COLORSPACE_RGB, 0) == 5)
+         internalFormat = GL_RGB5;
       else
          internalFormat = GL_RGB;