I have been dating for some 20 years now and I still feel the whole female vs. male psyche thing can be difficult to understand.  What about you?  I did find a website recently that a friend of recommended that helped to make learning about these relationships a little more fun and not so serious.  It really helps. Its called romance challenged com.  I hear that its new so I'm looking forward to watch as it develops.

From what I've read in the Mars/Venus books are that men get to a point early in the relationship, that they question whether they can make you happy or not.  They are wired to provide, and are encouraged when they know they are making you happy.  Evidentally they get to that point and withdraw to see if they are able to do that for you.  You should not only give them opportunity to succeed on that level, but make sure you let them know that you appreciate their efforts, and tell them the things they do that do make you happy.  They live for encouragement, appreciation, and trust from you.  It's hard to be at that point though, but be patient and they will come back around usually.