[amsat-bb] Problem getting into RS0ISS digipeater

I am using AGW Packet engine and UISS to work both NO84 and RS0ISS  however recently I have been having problems getting into the digipeater on the ISS. 25 watts of power and a 7 element M2 yagi. Is there a change in the packet modem on ISS or have they made some modifications that make it more difficult to access the satellite ?? Thank you  JACK  KC7MG