VIP - simple CTI to ITC always overflow/underflow

Still struggling with the CTI overflow issue... I've pretty much isolated my problem to the fact that the CTI overflows and then never will drive it's Avalon Stream Data Valid signal high again... Seems like it gets locked up and won't recover...

My system now consists of CTI, switch, triple frame buffer, polyphase scaler, switch, ITC... I get a good frame or two through and then the CTI locks up. I have it signal tapped and can see that from the read side of the frame buffer out through the ITC continues to work, but the CTI gets locked up.. I see that the ready signal into the CTI is high but the valid signal nevers goes high... I also see that the control packets coming from the CTI are correct but still no valid signal... I can clear the overflow by turning off the CTI, clearing the sticky bit via the control port, but as soon as I turn the CTI back on it almost immediately goes overflow again... At the same time that this is happening I never see the valid signal go high so it is obvious that the input fifo of the CTI overflows again....

Any help would be appreciated...

david