UPDATE
On a whim, I popped Red Dead on multiplayer into my X Box last night and HEAVENS BE PRAISED if I didn't get a good two hours multiplayer AWESOMENESS with NO hacking or cheating anywhere in sight!
No bullets coming through walls from buildings away, no disappearing and re-appearing players, no weird stuttering, sliding character sprites, no invisible weapons.
Was I just lucky? Have the awful hackers moved onto newer multiplayer games? Or have Rockstar sorted them out?
I did have to two new updates waiting to upload as soon as I signed in. Have Rockstar fixed this or patched something?

I think you are right.
RDR Multi-player on X Box 360 is pretty much unplayable now. It seems like it's been hacked to death.
Bullets fly through buildings and kill you. You no longer see who shot you. Characters disappear and re-appear.
This is a damn shame, because RDR was probably the BEST multi-player game I had.

I have the same prob. I don't think it was the update. I think some one caused a virus
"To crush your enemies, see them driven before you, and to hear the lamentation of their women"