I have an iPhone 4S (on O2), and have my Gmail account set up for push via Google Sync (http://support.google.com/mobile/bin...&answer=138740). It has been set up this way since 2009 on iPhone 3GS, then iPhone 4, and now iPhone 4S. It has always worked without any troubles whatsoever.
But for the last few days, I keep getting an error message saying, "Password Incorrect. Enter the password for the Exchange account." Initially I re-entered the password and it worked OK for a few hours before giving me the same error. However, today I had to turn my phone off (for an unrelated reason) and ever since I put it back on, it won't accept my password as correct, even for a few hours. As a temporary measure, I have been using the Gmail iPhone app (same password, but works fine).
I tried deleting the e-mail account, resetting my phone then setting up the e-mail account again from scratch. Same error message.
Today I also got a message from my sister, who is on Orange, saying her iPhone 4S has also been giving her the same message since Saturday (her e-mail account is with hotmail.co.uk).
We are both running iOS 5.1.1.
Any reason this could be happening or even better, a fix? It's weird that it started around the same time for both of us, but we are on different networks and use different e-mail providers. Does this mean the problem is at Apple's end?