"Initial Resolution" is a song variable, rather than a program preference. Hence, until now it has been stored with the current song, rather than with the current program preferences - it's appearance in "Preferences (F12)" is simply a nod to tradition, since IT2 displayed it under "Song Variables (F12)". Closing and re-opening reViSiT creates a new module and therefore resets the Initial Resolution to the default (which is 6). Simply hiding or showing the editor window will not reset this value - so you only have to set it one session. However, I have changed the scheme a bit now (in v0.88.1 - coming shortly), so that a copy is saved with the program preferences as well - and will be used for new songs, reViSIT instances, etc.

All the best,
Chris