On page 31 of the User Manual it CLEARLY says that in order to save a MULTI you click on the 3 bars right above C0, and to the left of the Search prompt. However, after changing the MIDI channels to the way I wanted them THREE TIMES AND I rescanned just for good measure. STILL when test to see if ST3 kept my changes by loading an old MULTI, then reloading the one I made changes in, the changes aren't there.
ST2.5 had the SAME VERY confusing Save/Save As issues. You can NEVER tell WTH you're saving. So, looking at page 31 in the manual, tell me WTH I'm supposed to do to save a MULTI!