You have to manually expand it the first time you open a second window, not use the maximize button. Then IE will remember how big you want it and use that size for all subsequent windows. Worked for me in 5.0.1 and 5.5 beta (currently, haven't tried 5.5 final yet). The start-minimized view was asked for by many people according to MS. Those people did not want to confuse daughter windows with the first one.