I am gstreamer in freescale processor. that is working fine for one time when i use gst-launch. but when i do for secand time it is not working. see the error

root@freescale ~$ gst-launch filesrc location=/root/yuvraj.mp4 ! mfw_mp4demuxer
! queue max-size-buffers=0 max-size-time=0 ! mfw_vpudecoder ! mfw_v4lsink disp-w
idth=990 disp-height=850 demux.
MPEG4PARSER_05.14.00 build on Aug 6 2009 13:54:26.
MFW_GST_MP4_PARSER_PLUGIN V1.6.0-r1 build on Jan 15 2010 12:23:05.
MFW_GST_V4LSINK_PLUGIN V1.6.0-r1 build on Jan 15 2010 12:23:10.
Setting pipeline to PAUSED ...
[INFO] Product Info: i.MX51
VPU Version: firmware 15.2.0; libvpu: 4.7.0
MFW_GST_VPU_DECODER_PLUGIN V1.6.0-r1 build on Jan 15 2010 12:22:55.
video type(0):33.
Pipeline is PREROLLING ...
[ 1932.880000] *** cs8556 lcd_fb_event
[V4L Display]: left=5, top=56, width=984, height=736
ERROR: from element /GstPipeline:pipeline0/MfwGstVPU_Dec:mfwgstvpu_dec0: fatal error
Additional debug info:
Allocation of the Frame Buffers Failed
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
FREEING pipeline ...
root@freescale ~$

So please help me why it happens. how to overcome this. thanks in advance