The rotaries on the x52 are seen as analog controlers,as such if you have combat trim on they will not override the "CT" command.
I have an X52 as well and use the rotaries to adjust my trim,so I use a button to disable "CT" or toggle it on or off,then I use the rotaries to adjust the trim.
So you have a couple of options,1) set combat trim in preferences,flight to off.2) set a button to toggle combat trim on/off.3)leave combat trim on and allow it to control the trim settings for you.
90% of the time I have "CT" on and dont bother with the trim,however there are times when I'll toggle it off and adjust the trim manually.
BTW. the urban myth that trim can somehow make you turn better is just that a "MYTH"....
hope this helps,if you have any other questions feel free to ask away.