^^ Excellent points ^^
I may have misunderstood the OP.
I thought the question was about the position of the various toolbars (which one on top of which), rather than opting whether or not to display them.
With so many ways to customize Firefox (and with so little detail provided by the OP), I may well have missed the point.
Thanks for the helpful hint - it's certainly any easy way to fix what might be the actual issue the OP reports.
Cheers,