On my iPad2 I have started to get repeated pop-up notices saying Invalid Exchange Password, please enter password. I have also had an email from Gmail that someone attempted to enter my account other than myself. Are these pop-up notices genuine or part of a hacker's plan to get my password.? Should I keep cancelling it? Any advice would be most welcome. I have at their suggestion just changed my GMail password.

Ah yes, Google and its paranoia. Here is the issue. Google tracks where you connect from to get Gmail. If it sees a brand new IP that isn't close to anything you have used before it will actually lock out that IP until you confirm it is good. So you need to read the email from Google and follow its instruction unless you want to just enter in your password when you are on a foreign IP.

You said you changed your gmail password, so I'm going to take a guess here that your gmail account on your iPad is seup as an exchange account. If so, the iPad is telling you that you need to update your password in the Settings app

Edit: forgot, but if gmail disables your account for suspicious logins it disables both the imap/pop, and Exchange logins until you login on the site and deal with the warning. the iPad will prompt for a new password in that situation as it only knows the password it has isn't working.

Thank you both very much. I reset Google password and then entered that in pop-up box and everything, touch wood, seems fine. I expect some would-be hacker may have entered the wrong password. Security must be very good with Google, which is reassuring.