When trying to sculpt corrective shapekeys on an armature deformed mesh, the smooth and fill/deepen brushes do not work at all, and the layer brush does not give any updates in the 3D view until another brush is selected and used.

See attached blend for example.



System info:
============================================
= Blender 2.56 (sub 5) System Information =
============================================


Blender:
============================================

version 2.56 (sub 5), revision 35899. Release
build date: 2011-03-31, 07:04:03
platform: Linux:64bit
binary path: /opt/blender25/blender
build cflags: -pipe -fPIC -funsigned-char -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -fopenmp -O2 -O2 -fopenmp
build cxxflags: -pipe -fPIC -funsigned-char -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -fopenmp -pipe -fPIC -funsigned-char -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -fpermissive -D__STDC_CONSTANT_MACROS -fopenmp -O2 -fopenmp
build linkflags: -L/home/sources/staticlibs/lib64
build system: SCons

Python:
============================================

version: 3.2 (r32:88445, Mar 29 2011, 15:35:00)
[GCC 4.3.2]
paths:
/opt/blender25/2.56/scripts/addons
/opt/blender25/2.56/scripts/startup
/opt/blender25/2.56/scripts/modules
/opt/blender25/2.56/python/lib/python32.zip
/opt/blender25/2.56/python/lib/python3.2/
/opt/blender25/2.56/python/lib/python3.2/plat-linux2
/opt/blender25/2.56/python/lib/python3.2/lib-dynload
/opt/blender25/2.56/scripts/addons/modules
/opt/blender25/2.56/scripts/startup/vb25/plugins

Directories:
============================================

scripts: ['/opt/blender25/2.56/scripts']
user scripts: None
datafiles: /home/ben/.blender/2.56/datafiles/
config: /home/ben/.blender/2.56/config/
scripts : /opt/blender25/2.56/scripts/
autosave: /home/ben/.blender/2.56/autosave/
tempdir: /tmp/

OpenGL
============================================

renderer: GeForce 9800 GT/PCI/SSE2
vendor: NVIDIA Corporation
version: 3.3.0 NVIDIA 260.19.06
extensions:
GL_ARB_blend_func_extended GL_ARB_color_buffer_float
GL_ARB_compatibility GL_ARB_copy_buffer GL_ARB_depth_buffer_float
GL_ARB_depth_clamp GL_ARB_depth_texture GL_ARB_draw_buffers
GL_ARB_draw_elements_base_vertex GL_ARB_draw_instanced
GL_ARB_ES2_compatibility GL_ARB_explicit_attrib_location
GL_ARB_fragment_coord_conventions GL_ARB_fragment_program
GL_ARB_fragment_program_shadow GL_ARB_fragment_shader
GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB
GL_ARB_geometry_shader4 GL_ARB_get_program_binary
GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging
GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_multisample
GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_occlusion_query2
GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite
GL_ARB_provoking_vertex GL_ARB_robustness GL_ARB_sampler_objects
GL_ARB_seamless_cube_map GL_ARB_separate_shader_objects
GL_ARB_shader_bit_encoding GL_ARB_shader_objects
GL_ARB_shading_language_100 GL_ARB_shadow GL_ARB_sync
GL_ARB_texture_border_clamp GL_ARB_texture_buffer_object
GL_ARB_texture_compression GL_ARB_texture_compression_rgtc
GL_ARB_texture_cube_map GL_ARB_texture_env_add
GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar
GL_ARB_texture_env_dot3 GL_ARB_texture_float
GL_ARB_texture_mirrored_repeat GL_ARB_texture_multisample
GL_ARB_texture_non_power_of_two GL_ARB_texture_rectangle
GL_ARB_texture_rg GL_ARB_texture_rgb10_a2ui GL_ARB_texture_swizzle
GL_ARB_timer_query GL_ARB_transpose_matrix
GL_ARB_uniform_buffer_object GL_ARB_vertex_array_bgra
GL_ARB_vertex_array_object GL_ARB_vertex_buffer_object
GL_ARB_vertex_program GL_ARB_vertex_shader
GL_ARB_vertex_type_2_10_10_10_rev GL_ARB_viewport_array
GL_ARB_window_pos GL_ATI_draw_buffers GL_ATI_texture_float
GL_ATI_texture_mirror_once GL_S3_s3tc GL_EXT_texture_env_add
GL_EXT_abgr GL_EXT_bgra GL_EXT_bindable_uniform GL_EXT_blend_color
GL_EXT_blend_equation_separate GL_EXT_blend_func_separate
GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_compiled_vertex_array
GL_EXT_Cg_shader GL_EXT_depth_bounds_test GL_EXT_direct_state_access
GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_draw_range_elements
GL_EXT_fog_coord GL_EXT_framebuffer_blit
GL_EXT_framebuffer_multisample GL_EXTX_framebuffer_mixed_formats
GL_EXT_framebuffer_object GL_EXT_framebuffer_sRGB
GL_EXT_geometry_shader4 GL_EXT_gpu_program_parameters
GL_EXT_gpu_shader4 GL_EXT_multi_draw_arrays
GL_EXT_packed_depth_stencil GL_EXT_packed_float GL_EXT_packed_pixels
GL_EXT_pixel_buffer_object GL_EXT_point_parameters
GL_EXT_provoking_vertex GL_EXT_rescale_normal GL_EXT_secondary_color
GL_EXT_separate_shader_objects GL_EXT_separate_specular_color
GL_EXT_shadow_funcs GL_EXT_stencil_two_side GL_EXT_stencil_wrap
GL_EXT_texture3D GL_EXT_texture_array GL_EXT_texture_buffer_object
GL_EXT_texture_compression_latc GL_EXT_texture_compression_rgtc
GL_EXT_texture_compression_s3tc GL_EXT_texture_cube_map
GL_EXT_texture_edge_clamp GL_EXT_texture_env_combine
GL_EXT_texture_env_dot3 GL_EXT_texture_filter_anisotropic
GL_EXT_texture_integer GL_EXT_texture_lod GL_EXT_texture_lod_bias
GL_EXT_texture_mirror_clamp GL_EXT_texture_object
GL_EXT_texture_shared_exponent GL_EXT_texture_sRGB
GL_EXT_texture_swizzle GL_EXT_timer_query GL_EXT_vertex_array
GL_EXT_vertex_array_bgra GL_IBM_rasterpos_clip
GL_IBM_texture_mirrored_repeat GL_KTX_buffer_region GL_NV_blend_square
GL_NV_conditional_render GL_NV_copy_depth_to_color GL_NV_copy_image
GL_NV_depth_buffer_float GL_NV_depth_clamp GL_NV_explicit_multisample
GL_NV_fence GL_NV_float_buffer GL_NV_fog_distance
GL_NV_fragment_program GL_NV_fragment_program_option
GL_NV_fragment_program2 GL_NV_framebuffer_multisample_coverage
GL_NV_geometry_shader4 GL_NV_gpu_program4 GL_NV_half_float
GL_NV_light_max_exponent GL_NV_multisample_coverage
GL_NV_multisample_filter_hint GL_NV_occlusion_query
GL_NV_packed_depth_stencil GL_NV_parameter_buffer_object
GL_NV_parameter_buffer_object2 GL_NV_pixel_data_range
GL_NV_point_sprite GL_NV_primitive_restart GL_NV_register_combiners
GL_NV_register_combiners2 GL_NV_shader_buffer_load
GL_NV_texgen_reflection GL_NV_texture_barrier
GL_NV_texture_compression_vtc GL_NV_texture_env_combine4
GL_NV_texture_expand_normal GL_NV_texture_multisample
GL_NV_texture_rectangle GL_NV_texture_shader GL_NV_texture_shader2
GL_NV_texture_shader3 GL_NV_transform_feedback GL_NV_vdpau_interop
GL_NV_vertex_array_range GL_NV_vertex_array_range2
GL_NV_vertex_buffer_unified_memory GL_NV_vertex_program
GL_NV_vertex_program1_1 GL_NV_vertex_program2
GL_NV_vertex_program2_option GL_NV_vertex_program3
GL_NVX_conditional_render GL_NVX_gpu_memory_info
GL_SGIS_generate_mipmap GL_SGIS_texture_lod GL_SGIX_depth_texture
GL_SGIX_shadow GL_SUN_slice_accum