Not sure what the issue is, but Gmail push through Microsoft Exchange stopped working for me a number of days ago and hasn't come back. I've deleted and re-entered my account, but no change. Rebooted, respringed, all that. Never had problems in the year since I've had an iPhone and it doesn't seem this is a system-wide issue.

Using a jailbroken unlocked 2G on T-Mobile web2go. Only change I've made was the new Opera Open mod in SB Settings, but I don't think it's related to that as it still happens if its toggled off. Edge and Data are still toggled on, but 3G isn't because (obviously) I don't have 3G.