my email is broken too. seems to have done it since 1.1.1 too, but i've been fairly busy with school since then to worry about it and have been checking manually. since re-setting up gmail with imap the other day i was sad to discover this didn't fix the problem.
i have my university email and gmail imap setup on this phone with the gmail as the primary. it also did this when gmail was pop3. the thing has been kinda random too, sometimes autoupdating a few times a day, other times going days without auto-updating only to do it again out of the blue. i've restarted numerous times. i'm really hoping there is some other solution other then restoring my iphone since that is such a pain. btw it has never been hacked. i've missed several important emails where i needed to get back with someone within minutes of business close because i get busy with class and forget to keep or can't keep manually checking all the time. it's so annoying!
any help would be amazing, is there some obscure setting that changed in gmail that i need to alter or something new in 1.1.1? i'm pretty sure i checked into everything i could with that but maybe i missed something. thanks in advance.