Setting it aside and never coming back to it is not necessarily a bad thing...worse would be to "set things aside" but continually dredge them up whenever you're angry. Words of wisdom from my mom a looooooong time ago: What's past is past; don't escalate a new argument with old arguments.
oh yeah, if you had a stupid fight about squishy grapes, maybe let that one go. I think what 00 was getting at was the ones that do matter and you just ignore it and never resolve or talk about the underlying issue and let it fester instead.