My daughter used to love playing with toys traditionally associated with boys. A big part of this is that her mother used to frequently (6-7 days a week, 8+ hours) watch her male cousin who is only a year older. My daughter's ALWAYS had a girly girl component interested in jewelry, make-up, fashion etc, but her favorite toys were toys car/trucks, trains, playing in the dirt, and worms (although the girly girl portion hates bugs, but worms some how are okay) etc.
Then during Kindergarden it changed. I first had the evidence needed when she tried throwing her toy cars away saying they were boy toys. I asked her why she was crying and she said because said girl can't play with cars. I of course called the teacher and when she insisted she wasn't sexist, I called the prinipal and said explicitly I'm not calling her a sexist, I AM saying that she made an impression on my daughter that she wasn't allowed to play with certain toys because they were for boys. All the principal would do was insist the teacher wasn't sexist. Frankly, if the teacher was, at least then I could understand the problem. If she isn't why is my request that she be more careful about what she says (this wasn't the first sexist problem; I'm a single dad and the teacher kept telling my daughter have your mom buy you a new back pack because I don't like this one even after I wrote her numerous notes saying I'm a single dad and day-to-day purchases and care are my responsibility) and sit down and tell my daughter it was just a misunderstanding and she can play with things like cars if she wants to.
Its only been since her mom got her an EEE-pc for Christmas this year (First grade) that I've really seen a change. Suddenly she's interested in computers and asking me how our wireless internet works. If I'm on the computer, she asks if I'm fixing it and if so how. Or she found the astronomy program and she's wanting to look at stars. Or she used to be REALLY into biology since she saw her uncle gut a fish, and she's asking to look up things on what the insides of animals look like. I don't think I would have bought a first grader a laptop, but its brought my daughter back.