GuiGuy
At what point do you believe the event is being called?
If you are trying to initialise fields it sounds like you are expecting the onBeforeInsert to run at the point just after you click Add New button, i.e after clicking the New button but before the form is displayed? I’m sure you know this, but that’s not the case? Perhaps just can’t see the woods for the trees (like my recent virtual fields in searches snafu)? So just a recap of what I know you already know… 
onBeforeInsert will run at the point you try and save a new record - so if you were trying to initialise fields on a “new” form, then that bit has long gone by the time onBeforeInsert is run. You need to use onLoad instead, and check if fields are null / empty - and then initialise if needed.
Or are you - at the save / update record point - wanting to initialise / set either hidden fields or fields in other table fields - in which case onBeforeInsert or onBeforeUpdate respectively are the right places.
