Are you even hearing yourself? Let me show you a couple things that you said:

Quote Originally Posted by Charcoal
As a sequel to FFVII, AC doesn’t do much wrong. It’s just that it’s what you call an add-on, and some of us who were happy with FFVII proper don’t want stuff like that.
So for those of us who would like to stick to the 1997 FFVII this tainted lifestream concept becomes a plot hole because it’s pure sequel material.
I've boldened the parts I deem important in these quotes. The problem that you have with the Compilation is that you don't like or want sequel material. That's all fine and dandy but it doesn't change the fact that there is. Yes, VII is a great stand alone game, but obviously there are things that led up to the events in VII, and things that happened after the events in VII. All the Compilation is doing is giving us more of a world we already love. Oh, and do you even know what a plot hole is? You seem not to, so here's the Wikipedia definition of the word:

Quote Originally Posted by Wikpedia
A plot hole is a gap in a storyline that goes against the flow of logic set-up by the plot or that undermines the basic premises of the story. Plot holes are usually seen as weaknesses and flaws in a story, and writers try to avoid them (except in certain deliberate circumstances, usually for humorous effect) to make their stories seem as realistic and lifelike as possible.
Now, I'm pretty sure that I just explained how Jenova tainting the Lifestream fits perfectly into the logical flow of the original game. Whether or not it was never intended is not the point right now. What matters is the logic and flow, because that's all that a plot hole is concerned with. Thus, as long as the explanation of the tainted Lifestream is consistent with the original game, which I've already shown that it is, it is not a plot hole.

Now, like I said, I don't think enough information has been given about stagnant Lifestream to determine whether or not it logically fits with the world that the original game set up. Also, if you could show me a specific example in Dirge of Cerberus where Vincent's elaborated past clashed with the skeleton of a past that we find out in VII, that would be a plot hole. But as such, you have not shown me such an example yet. If you believe it exists, please tell me.

I will check in both games the passage of which you speak (lucky me I just started playing both games again after a good six month hiatus from them) and get back to you on whether I truly believe that it is a plot hole or not. Until you can show me an example of this or any other plot hole, based on the definition above, not whatever definition you were using before, then we'll have made some progress here.