i had been having a problem with my yahoo! mail. when i would compose an e-mail to someone i would send it and it would be fine, but i would get hundreds of copies in my "sent folder" in yahoo! mail. i finally figured it out: i had placed my own name and e-mail address in my contacts(so i could e-mail myself pics from my phone), well, i deleted myself out of my contacts, and no more copies in my sent folder. somehow having my e-mail address in my contacts along with the same e-mail address being set up in my nexus one did not jive, it did not like it. so, i think i got it fixed!