I am using a 1.1.1 image with SystemBrowser defaultOpenBrowser OBSystemBrowserAdaptor I am debugging some code that I have not used for a while, so a few growing pains would not be a surprise. What DOES surprise me is the following: (1) select #plotFrom:to:using:keepGoing:plots: and accept the code; no errors are reported; fair enough (or is it?). (2) edit the source (even just adding a harmless new line) and accept, and the compiler (correctly, it appears) complains that arguments are already defined. I suspect the arguments are indeed stomping on instance variables that I added during the past year, and that confusion is the source of some seriously strange looking behavior. The point is that accept is apparently doing nothing or failing silently until I actually edit the source. I greatly prefer the error messages to silence; I assume the silence is related to a desire to get code loaded intact rather than having MC bark mid-load?? Bill