So I downloaded the latest patch and started again from scratch with this game, after already wasting 50 hours + on two other aborted playthroughs.

All had been going ok until I got to Nipton. As I approached the Legion to trigger the conversation with Vulpes Inculta, I suddenly notice red bars on my radar. The entire group of Legion soldiers including Vulpes Inculta are hostile towards me for no reason. I am wearing plain leather armour so it's not like I'm wearing NCR faction armour or anything that would trigger hostility. It shows that I am neutral with the Legion, I am also neutral with the NCR so it's not like they would be attacking me because I'm big buddies with the NCR or anything like that.

I'm finding it annoying because on this playthrough I intended to be a bad guy and side with the Legion, but it looks like they will treat me with hostility no matter what.

So is this a bug?? Or could I be doing something or have done something earlier on in the game to make the Legion hostile towards me??

It's strange, because on my previous aborted playthroughs on 1.01 it seemed to work the other way round. I became vilified with the Legion, but they would never act hostile towards me. They would always show as yellow on my radar and I would have to fire shots and aggro them to make them hostile.

Well this could be a bug, but an unexplainable one

For me, i am "accepted" by the NCR, yet all and any NCR members(excluding drunk ones) shoot at me
this happened before and after 1.02 update...

Plus this couldn't be because of what you've done because what i believe is that your first experience with the Legion (unless you pass sloan and head north) is at Nipton so there would be no reason for an attack...

I feel like I shouldn't have to say this but check your armor and make sure it's not faction..

Did you not read my post???

Did you wear faction armor and put it in a container when you were still wearing it? Or did you use it for repairs?
If so, the game might still think you are wearing faction armor. To fix these bugs you must find another set of
the faction armor and equip/unequip it. I don't know if these bugs were fixed with the last patch, so if this is not
it, afraid I don't know what is...

Yes, I wore NCR Bandolier armour earlier on in the game.

I think I've worked out what might have happened here. Because I was playing as a badass I decided to pickpocket Malcom Holmes in the wastelands to steal his Sunset Sarsaparilla Blue Star Bottlecaps. However he caught me in the act and then a wierd glitch happened. I was wearing the NCR Bandolier armour at the time and as soon as I got caught pickpocketing, the NCR armour 'disappeared', and my character was left wearing no armour at all. A quick check in my inventory revealed that the armour had dissappeared completely.

Going off what you are saying about the equipping/unequipping faction armour, I am presuming the game is still thinking that I am wearing the NCR armour.

I will try to track down some more NCR armour and equip/unequip it to see if that works.

So much for 1.02 being a 'comprehensive' patch then............

I managed to get hold of some NCR armour. I equipped/unequipped it and then headed back to Nipton. It worked, the Legion were no longer hostile, so this is the solution if anybody else is affected by this bug. Thanks.