I posted this a loooong time ago, and I never got the answer for it - but I can't see HP or armor bars ontop of peoples' heads.
I don't know if this helps - but I have the Steam version of San Andreas.
And before this is an "answer" - no I do not have any mods that would have an effect on this as I have never been able to see them since I started playing SAMP.
How do I get it so that they can appear?