Huge problem with Handles.FreeMoveHandle

So, I call Handles.FreeMoveHandle in OnSceneGUI() of a custom inspector to create handles for a bunch of points the script needs to modify. Soon however, at intervals the whole system lags and then eventually this turns into monodevelop/unity freezing.

Am I using this wrong? Should I call it in response to a certain event, or after some check? Am I supposed to re-use handles? I’m very confused and will be grateful to anyone who can clear this up for me.

Thanks!

Hope it isn’t a problem if I bump this, pls help :).