Several of our staff have been unable to use Google Sync for iPhone lately. They entered the correct credentials, but the phone just kept saying “password incorrect”.
The fix for this issue was simple. I actually contacted Google Enterprise support and they sent me the link: ( it is specific to our domain, for plain old Gmail users visit: https://www.google.com/accounts/UnlockCaptcha )
1. Log in to Google Apps ON THE PHONE in Safari.
2. Visit the link above (https://www.google.com/a/asd.edu.qa/UnlockCaptcha)
3. Enter your Google Apps username (not the whole email), password, and solve the Captcha riddle 😉 then submit.
4. Set up the iPhone as directed at: http://www.google.com/support/mobile/bin/answer.py?hl=en&answer=138740