scale-up on the DM642 video port

Hello everyone,

   I am trying to enable the 2-times hardware scaling feature on the
DM642 video port. I am using the EVMDM 642 board to test this.

   If the hardware scaling on the input and output video ports are
both enabled, things are fine.

   But a problem occurs if I try to do hardware scaling only at the
display port.
   I get an input CIF image from the SAA 7115, blow it to 352 * 480
and then do hardware scaling at the display port: the displayed image
is of correct size (720*480) and the luma is right. But the chroma
appears as bands across the screen instead of uniformly 

For testing all this, I have been using the ntsc.pjt and the
scaling.pjt projects provided by TI.

This is how I fill my displayBuffer before passing to the FVID driver:

		id = DAT_copy2d(DAT_1D2D, yVert, disFrameBuf->frame.iFrm.y1, 352,
480, 360);
		DAT_wait(id);
		
		id = DAT_copy2d(DAT_1D2D, uVert, disFrameBuf->frame.iFrm.cb1, 176,
480, 180);
		DAT_wait(id);
		
		id = DAT_copy2d(DAT_1D2D, vVert, disFrameBuf->frame.iFrm.cr1, 176,
480, 180);
		DAT_wait(id);
	Why does the hardware scaling not work right on the Chroma samples at
the output? 

 This hardware scaling becomes very important for us because it seems
to save a lot of time and the video quality is also very good.

 Thanks in advance for your time and help.

Regards
Suba.