Depends on the woman, and could also depend on the issues. Communication is a vital part of any healthy relationship, so either partner should feel like they can bring up a relationship issue and discuss it.
"Unhappiness" is quite general, so if you are thinking about bringing something up, I would suggest that you have specific issues in mind that are causing the unhappiness, because without any specific, it's hard to come up with a solution or compromise that might help - and it's also more likely to make your partner feel defensive, and put down.
The way you bring it up also makes a huge difference. Be sure to use phrases about how you feel, rather than just jumping what they do/don't do that makes you unhappy. The less accusatory you are, the less likely that she will feel threatened.
For example, don't say they make you unhappy, or the relationship makes you unhappy. You need to say that you are feeling unhappy, and these could be some of things that are contributing to the way you feel. Also remember when things get heated that this makes a big difference; there may only be a fine line between calling someone stupid, and calling their actions stupid, but it's there. It's important to make it less of a personal attack on the person, and more of a discussion about what they do, don't do, or could do to help the situation.
Most importantly, if you want to talk about it, it says you want the relationship to work, but you still might need to tell them that, and more than once, during the discussion. They understand you are bringing issues up because you want to work on them, not because you want to put them down, and find a way out.