I've been following your thread for a while, and keep seeing similarities between you and my H. H is also generally unhappy, especially with career, but has decided that he wants to stay in our marriage. But, like you, I don't think he'd actually say we have a "happy" marriage. There is on big difference, in that H left me for 6 months (came back 6/2007), so he's the WAS, not the LBS.
Anyway, I'm writing because I think I might understand some of what your wife is feeling right now... She's recommitted to the marriage and wants to make it work, and it to be HAPPY. She's frustrated that you're not happy, and doesn't know what to do to help with that. Maybe there's nothing she can do - which is also frustrating. Maybe there's something she can do, and she just doesn't know. If she has/does do anything that helps, I think the best thing you can do is be sure to acknowledge it. Give her some positive feedback, so she feels like there's hope and progress. Even if it's a really little thing. If you can think of something she could do, consider asking for it in DB kind of way.
Hang in there. - Treading
Me 41 H 42 M 11 years no children Bomb: 10/2006 "I'm better without you than with you." Separated: 12/2006 H moved back: 6/2007