[ixp1200] The PciDg Driver's problem

Hi, Dirk How are you doing? I just tested some program on the StrongARM, which transfer the packets between the uEngine and the Host PC. But I found it seems the PciDg module( the Pseudo Network Driver between Host and StrongARM) will lost packets in the transmission. I tested my program on the real network driver, it works fine. It only lost packets on PciDg driver. So do you have any infomation about this problem? I read some source code of the PciDg, but can't figure out the problem yet. Have anyone encountered this problem before? Please give some advices. Thank you very much. Victor