This method I found it by myself, it frees a little about 100 ~200 KB but I guess it's useful sometime
Close your menu not by selecting the right selection key "exit", or pressing the menu key another time, they only hide the menu app but do not close it, to close it select the left selection key "option" and scroll down and select "exit"
So when you open an app needs more ram reopen menu and close it, it's useful when play low bit rate video in realplayer paradis.