I couldn't reconfig slave receiver in cpri core

Recently I design auto-rate negotiation function with cpri and altgxb_reconfig core.

I could reconfig master and slave transimtter successfully, however I couldn't reconfig slave receiver.

I am using quartus 10.0 sp1; the start channel of slave receiver is the default value 4;altgxb_reconfig core is in continous write mode;rx_tx_duplex_sel is set to 0x01; logical_channel_address is set to 0x4; reconfig_mode_sel is set to 0x5.

But two reconfig_clk cycles after the write_all asserted, the busy signal is de-asserted and the error signal is asserted for two reconfig_clk cycle

Why that?