Problem of Matlab with gige camera video preview having scrambled lower strip

[Gigeguy]

I am trying to acquire video from a gige GenICam compatible camera. I am facing a problem of having scrambled lower group of rows. the code used to acquire the video and a sample of the video preview are shown below. could any body help me to solve this problem? Thank you.

vid = videoinput('gige', 1, 'RGB8Packed');
src = getselectedsource(vid);
src.TriggerCacheEnable = 'False';
src.ExposureTime = 6000;
src.PacketSize = 9014;
src.DeviceStreamChannelPacketSize = 8164;
src.PacketDelay = 1000;
vid.FramesPerTrigger = 240;
src.AcquisitionFrameRate = 90;
triggerconfig(vid, 'hardware', 'DeviceSpecific', 'DeviceSpecific');
preview(vid);
a=getsnapshot(vid);
imshow(a);