If I have a command with a default value for its single argument, and I issue the command, I get the accepting-values dialog, with a single input gadget containing the default value. I look at it and I say "That looks fine." So I press the OK. Then McCLIM complains that I haven't provided a value for all of the arguments. What McCLIM "wants" me to do is to select the argument input field, press RET to explicitly accept the default, and then press OK. This isn't really a bug, but seems pointlessly cumbersome... I'll see if I can fix it, but I'm probably not the optimal person to do so...