iPad Unsolved mysteries: Duplicate notification of gmail e-mails

After upgrading my iPad2 to 5.1.1 and jailbreaking, I am getting duplicate notifications for each e-mail I receive to my GMail account. My other e-mail accounts do not exhibit this problem. I removed the Gmail account and re-added it, but it still has the other problem.

I disabled all other e-mail accounts, but receiving an email through my GMail account results in duplicate notification. I do not get the duplicate notification on my iPhone 4 GSM 5.1.1/jailbreak. Any suggestions?

I get duplicate notification, even when the following settings (I tried to remove identifying information):

 

This is resolved now. By having both the inbox and the sent folder pushed, I was getting a notification for the e-mail I was sending (to myself) and for the email I was receiving (from myself). After unchecking the sent folder, all works as expected.