QUOTE(roi_aggie @ Aug 1 2008, 12:26 PM)

Honesty is still, and always will be, the best policy.
You don't have to show that you are currently a happily married couple. Though that would help, it is not what they are looking for. You only need to show that you entered into the marriage in "good faith" and did not, or are not, commiting marriage fraud.
It is up to the USCIS to prove otherwise.
There is actually a case of a person over here that they were in divorce proceedings and they disclose it and even so she got approved.
I think the best policy is that you two are through rough times but you still care for each other, that says a lot.
Be natural...and my advice is never give more than necessary but you must be natural, so if you feel that in the case it might get the impression that you are "covering up" the appearances, to say that you two are having a rough time and have spend to time in separation status...but still care for each other, I don't see major problem BUT you know it will really depends on the adjudicator that you will get.
Good luck.