[U-Boot] U-boot 2010.12 Ping failed on DP83849C

[Jerry Wang]

I have a custom MPC8313ERD board loaded with u-boot 1.1.6 and the network PHY is 
NetSemi DP83849C. The PHY info is copied from DP83865 and the network works 
fine.

Recently I am trying to upgrade u-boot to 2010.12 but I got Ping failed and host 
is not alive message when I ping the same host.
After enabling debug, it shows:
       Trying TSEC0        
        Speed: 10, half duplex
        Using TSEC0 device
        sending ARP for 0a350275
        ARP broadcast 1
        TSEC0: tsec: tx error
        ARP broadcast 2
        TSEC0: tsec: tx buffers full
        ping failed; host 10.53.2.117 is not alive

    After googling the problem, I learned this may be related to the some kind 
of bus conflict when DMA move ip packet to transmit bugger.
   My question is what caused this error in 2010.12 version and not in 1.1.6?