Today I've tried new SetTexOffset hook. (X server 1.4 + self-compiled xf86-video-intel from Aug, 16 2007 + self-compiled mesa from 4 Sept 2007).
Linux kernel 2.6.21.7
Drm from git, up to commit 06bb07259531d10df2c1979919af899e3812057b

My hardware is:

00:02.0 VGA compatible controller: Intel Corporation 82845G/GL[Brookdale-G]/GE Chipset Integrated Graphics Device (rev 01) (prog-if 00 [VGA])
        Subsystem: Micro-Star International Co., Ltd. Unknown device 5808
        Flags: bus master, fast devsel, latency 0, IRQ 17
        Memory at d0000000 (32-bit, prefetchable) [size=128M]
        Memory at dff80000 (32-bit, non-prefetchable) [size=512K]
        Capabilities: [d0] Power Management version 1

beryl - 0.2.1 It works fine with 16 bpp screen depth. But display nothing in 24 bpp mode. And i forced to reboot my machine via ACPI poweroff.

Probably this is related to this comment, found in i830_render.c

 I830FALLBACK("830/845G don't support a8, x8r8g8b8, x8b8g8r8\n"); 
(in src/mesa/drivers/dri/i915tex/i830_texstate.c I can see lines like this:

if (intelObj->imageOverride) {
      i830->state.tex_buffer[unit] = NULL;
      i830->state.tex_offset[unit] = intelObj->textureOffset;

      switch (intelObj->depthOverride) {
      case 32:
         format = MAPSURF_32BIT | MT_32BIT_ARGB8888;
         break;
      case 24:
      default:
         format = MAPSURF_32BIT | MT_32BIT_XRGB8888;
         break;
      case 16:
         format = MAPSURF_16BIT | MT_16BIT_RGB565;
         break;
      }
)