I just bought a zire 31 to keep some medical info and addresses on. I downloaded epocrates from their site (a smooth transaction) but then i tried to download (and sync) Mobile Merck Medicus as well as the PDR download I had at home. I came across a message both times and have no clue what it means (again I am new at this so bear with me). the zire has 16MB of memory on the handheld and I bought a Sans "disk" with 256MB on it. The message that kept coming up was, "there is no application on the organizer to handle this file (0x4005)". the mobile merck medicus file was 7.33MB and the PDR was 1.41MB. I tried to research this on my own and found very little information. What i did gather was that maybe a need a "card reader" for these apps??? any information would be greatly appreciated as i am lost in cyberspace here. thanks. ben