Periodically during the day I keep getting an error message saying that either my gmail username or password are incorrect i.e. gmail sign in error. Not sure what is going on because they are correct. I'm new to android and gmail so I ask for your help. I added the gmail account to the main email app along with a yahoo account before I realized that gmail had its own app. I don't see that this should be a problem but maybe so. The yahoo account doesn't miss a beat just the gmail account. Help.