I've been playing the game as friendly and as good as possible from the beginning, siding with NCR and doing quests for them. Mainly following the main questline up until Boulder City. My fame with NCR is "accepted" and I've mostly been wearing a NCR Face-Mask armor, but after the Boulder city main questline part, and helping those two NCR hostages escape then walking from Boulder to Tradepost 188..NCR has somehow turned on me, even though my Rep is "Accepted" and I've done nothing wrong or different since I first met them.

Been using ED-E and Boone as companions, So it shouldn't be anything with those two.
I've always been wearing NCR armor, but when I approach any NCR, they start shooting at me.
If I de-equip my NCR armor, then all NCRs turn red, even though i'm still "accepted", also NCR rangers will random pop up and start shooting at me. I was down in Vault 34, wearing a space suit for the radiation, and I would have NCR rangers come stalk me down there to try and end me.

I'm hoping a fix for this will also come soon.. cuz to me this it's pretty game breaking when the faction you've sided with is trying to kill you for some unapparent reason :/

Yeah the NCR reputation is pretty buggy. Though the bug I've encountered is way different than yours. Like you I've been wearing the NCR Wrap Armor as well, also for the entire game and helping the NCR with everything, but if I take that armor off I lose all my rep with them(just got them to Idolized last night). That's A LOT of hardwork that can just be undone just because I need to put on a Rad Suit to make it through highly radiated fields. It really hampers me from exploring such places as I want to keep my reputation high. Unfortunately, I probably won't play this game anymore until they patch this issue.

My solution has been this. If NCR attacks me on site I just kill all the ones attacking me. I find that it slightly hurts my rep with them but not enough to make non-glitched NCR troops attack me. As i continue to work with the NCR I build my lost rep back up until the next time some NCR troops glitch out and attack me. Annoying glitch, but I can get past it. Can't wait for the next update.

Sounds like there may be a bug related to reputation going specifically towards your disguise. In other words, all reputation gained is tied to your disguise and when you take it off it seems to revert. There are also problems where if you happen to kill one named/important NPC from a faction, they turn on you indefinitely. I encountered another person who had this happen to them with the Brotherhood of Steel. My guess would be that all faction reputations are bugged out and not just NCR.