gtk-demo interlaced problem

[ywkhong <ywkhong gmail com>]

Hi,
I'm using gtk with directfb and I having problem displaying the gtk-demo
correctly on the LCD (640x480, RGB666). The output of the gtk-demo looks
interlaced, but the directfb sample app looks fine.
How can I actually change the screen resolution and the other parameters
such as the interlace/non-interlace in the gtk-demo app?
While running the gtk-demo in the background, I tried fbset -fb /dev/fb/0
-laced 1 and launch the second copy of gtk-demo only then it looks fine.

I attach the fbset -i -fb /dev/fb/0 info below:
mode "640x480-120"
    # D: 25.641 MHz, H: 31.892 kHz, V: 119.894 Hz
    geometry 640 480 640 480 16
    timings 39000 85 70 32 11 9 9
    bcast true
    laced true
    rgba 5/11,6/5,5/0,0/0
endmode
Frame buffer device information:
    Name        : dm_osd0_fb
    Address     : 0x87000000
    Size        : 2073600
    Type        : PACKED PIXELS
    Visual      : TRUECOLOR
    XPanStep    : 16
    YPanStep    : 1
    YWrapStep   : 0
    LineLength  : 1280
    Accelerator : No
When running gtk-demo, this is what I got:
   ~~~~~~~~~~~~~~~~~~~~~~~~~~| DirectFB 1.2.1 |~~~~~~~~~~~~~~~~~~~~~~~~~~
        (c) 2001-2008  The world wide DirectFB Open Source Community
        (c) 2000-2004  Convergence (integrated media) GmbH
      ----------------------------------------------------------------
(*) DirectFB/Core: Single Application Core. (2008-09-03 04:01)
(*) Direct/Thread: Started 'VT Switcher' (-1) [CRITICAL OTHER/OTHER 0/0]
<8388608>...
(*) Direct/Thread: Started 'PS/2 Input' (-1) [INPUT OTHER/OTHER 0/0]
<8388608>...
(*) DirectFB/Input: IMPS/2 Mouse 1.0 (directfb.org)
(*) Direct/Thread: Started 'Keyboard Input' (-1) [INPUT OTHER/OTHER 0/0]
<8388608>...
(*) DirectFB/Input: Keyboard 0.9 (directfb.org)
(*) DirectFB/Graphics: Generic Software Rasterizer 0.6 (directfb.org)
(*) DirectFB/Core/WM: Default 0.3 (directfb.org)
(*) FBDev/Surface: Allocated 640x480 16 bit LUT8 buffer (index 0) at offset
0 and pitch 1280.
(gtk-demo:1283): Gdk-CRITICAL **: gdk_drawable_set_colormap: assertion `cmap
== NULL || gdk_drawable_get_depth (drawable) == cmap->visual->depth' failed
(*) Direct/Thread: Started 'EventBufferFeed' (-1) [MESSAGING OTHER/OTHER
0/0] <8388608>...
(gtk-demo:1283): Gdk-DirectFB-WARNING **:
gdk_display_request_selection_notification Unimplemented function

(gtk-demo:1283): Gdk-DirectFB-WARNING **: gdk_window_set_keep_above() not
implemented.

(gtk-demo:1283): Gdk-DirectFB-WARNING **: gdk_window_set_keep_below() not
implemented.


While gtk-demo running in the background, I fbset -i -fb /dev/fb/0 and got
the following:
mode "640x480-60"
    # D: 25.641 MHz, H: 31.892 kHz, V: 59.947 Hz
    geometry 640 480 640 480 8
    timings 39000 85 70 32 11 9 9
    bcast true
    rgba 8/0,8/0,8/0,0/0
endmode
Frame buffer device information:
    Name        : dm_osd0_fb
    Address     : 0x87000000
    Size        : 2073600
    Type        : PACKED PIXELS
    Visual      : PSEUDOCOLOR
    XPanStep    : 32
    YPanStep    : 1
    YWrapStep   : 0
    LineLength  : 640
    Accelerator : No
I'm want to know how to change the gtk-demo app to set the fbset to the
following which is different from the fbset info before running the gtk-demo
laced = false,
rgba 8/0,8/0,8/0,0/0,
LineLength  : 640
Hope someone can help. Thanks.
-WK