Arria II GX: Transceiver CMU PLL Reset

Hello,I have a problem with resetting my transceiver design.I'm testing on the Arria II GX Devkit and I'm using Quartus 9.1sp1.Sometimes after I pushed the reset button the transmitter sends wrong bits over the HSMC loopback header.In the tx reset controller the pll_powerdown is set for more than 1us as mentioned in the Device handbook on page 505.If the failure occured and I set the tx_digitalreset via an other button the problem stays.So I think there must be a problem with the CMU PLL, but the pll_locked signal stays high.I synchronize the inputs and added some debouncing for the push buttons.I verfied the data is correct that goes in the altgx component with Signaltap.I also looked with an oscilloscope on the serial data line. With the decoder in the oscilloscope the failure is visible. It cannot decode all characters.I could not see any abnormality in the eye diagram. But I'm not so familiar with the oscilloscope yet.Does anybody have an idea?Thank you!Kippis