the 4th video input conflict with tcp/ip in JPEG_netcam of DM642

Dear all,
I want to capture the video with the 4th video port,and I have succeed in
3 video inputs,but i found that the the 4 the video conflict with the
tcp/ip in the jpeg_netcam example.I think it the EDMA conflict,
because,when the VPORTCAP_Params parameter:  "irqId"!=14,the other video
and the network can initial successfully; but when irqId=14,the network
cann't initial and the video cann't initial either.
Who have been working on this example,help me!
Thanks all.