Hi Marco, do you mean you want to separate the tool palettes on the side pane so that there is only one tab for each palette?

For MoI version 4 you can do this by installing a startup script as descrbed here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=9439.3

For MoI v3 it is possible but it's more involved, you need to edit the UI, there is some information on how to do that here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=8064.1

- Michael