I was also having problems with Push on my Gmail account. I thought just having IMAP enabled in the Gmail settings menu was enough. I then read a post somewhere in this form (I forgot where). The post stated that you must also choose the selection: Enable POP for mail that arrives from now on. I enabled that setting in Gmail, via my laptop. My Push is now blazing fast. It's amazing to me, how we can learn something new everyday.
Kudos to the forum, another problem solved!!! Mark