considering the incest found, otherwise, in the Old testement I'm not sure that it's really necessary to require the first and second chapters of Genesis to address different time frames. Indeed, the bible is a minefield full of potential variations of interpretation. I, myself, am no believer so I have no reason to insist that mine is the correct interpretation. That being said, I would have to ask, is it only the potential of Incest in Eden the reason why you believe ch1 and ch2 are relating different tales? if so, might I suggest the following:
While incest was clearly against the law of Moses there are more than a few examples of such. Perhaps each circumstance was recorded for historic reference rather than validation. Even so, the Laws of Moses were still given unto the people by a MAN, not a god. WHEN DID GOD EVER DECLARE ANYTHING ABOUT INCEST? Moses wasn't the first to make the same claims. Now, christians are required to believe that Moses got his marching orders from god much like Mormons think about their patriarch and every other group of dogma followers think about their version of Moses. My atheist argument is that the Law of Moses was a direct reflection of the culture of jews that he was leading. Indeed, the worship of the golden calf indicates that Moses has a motivation to bring back commandments that DIRECTLY reflected the behaviours of his people. If so, then the OT really doesn't have ANYTHING, besides traditions of man, to say about how GOD thought of the act of incest. Would the alpha and omega who just got done creating the world give a damn about human taboos if his new humans were sexually active? BEFORE eve ate the apple and THEN felt shame in their nudity? If GOD created Adam and Eve and saw that "everything was good" why would he have ignored the taboo of incest among his new humans? Is god similarly critical of incest among other created animals? Until Eve ate the apple were she and Adam supposed to behave like animals? I'm betting that incest was a sin declared by MAN instead of GOD given the absence of godly indication until MAN had something to say about it.
Now, regarding the 1st and 2nd chapters of Genesis I brought up the timeline of each because they match. In Ch 1 God creates the Heaven and the earth (1:1) before separating water from land (1:7) before seeding the earth (1:12) before creating man (1:26). Ch 2 indicates the creation of the earth (2:4) before the watering of the seeds which were in the created earth (2:5) before misting the land (2:6) before creating man (2:7). They match and there is no indication, beyond an aversion to a human taboo, that they are separate circumstances.
Finally, and I think most indicative, is Gen 2:1-3
1 Thus the heavens and the earth were finished, and all the host of them. 2 And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made. 3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made. 4 These are the generations of the heavens and of the earth when they were created, in the day that the LORD God made the earth and the heavens
Again, as an Atheist, I have no dog in this race but I'm not quite seeing any indication from the bible of two seperate events that go on to sidestep the issue of incest. But, you are correct insomuch that interpretation varries. Hell, 2:4 leaves lots of room for evolution. The fact that the Alpha and Omega needed to REST seems to limit gods very supposed nature. The pluralistic "Our image" is a pandoras box of possibilities. I guess I was just curious about your interpretation because It's easier to accept the beliefs of the faithful when they think critically about what, exactly, they believe in rather than following suit and custom. I would imagine that an omnipotent god would not have missed the incest potential when only making two humans in eden. Then again, who says that the same god who just created the earth couldn't have also created enough variations in eve that Adams rib bone would not have to indicate incest? It's not like eve was the product of sexual reproduction, eh? If anything, Eve is more of a CLONE produced by asexual budding.
For what it's worth, I'm not trying to change your mind at all. I have my own opinions regarding the creation myth and the specific things mentioned in the origin tale. I'm betting that the tree of knowledge allagory is a direct relfaction of the point where an evolving human stopped being merely an animal and started using reason instead of just instinct.
Slept good, got up early, worked smart and hard. Great American Day. 
