I just got Igor 6.02 installed and running. Seems fine in a quick perusal. The previous problem noted with the help browser (no window/decorations around it) still exists, making it hard to move an close. As a workaround, it can be moved by stretching the window towards where you want it, then similarly compressing the other side to get the same shape back. Closing it with ctrl-w still works.
I will try more with it later (large custom macros & programs and large data sets); it new problems arise, I will post a followup.
-Andy