A little background...I've only had my Nexus 7 for 1 week and just love it...I'm actually addicted to it.
When I first set up all my GMail & Calendar stuff, it "looked/seemed" fine. But after using it for a week, I started to notice a small issue, which is actually a BIG issue
The Gmail App wasn't auto-syncing properly. By properly I mean like hardly ever. It would randomly notify me of incoming emails, sometimes it took over 50 minutes to notify me, other times it took hours, sometimes even 10 minutes. It was all over the place. Weird!
I did the obvious and went through EVERY
setting possible. In fact I even spent over an hour on the phone with Google support. I stumped Google support. They could not figure it out.
Google & I went as far as resetting the entire tablet back to factory defaults....still not luck!
** I found the solution and I think everyone should know this **
Instead of using the GMail App, I setup and used the default Email App (the yellow email icon). This Email App allows you to setup the sync refresh interval...and it actually WORKS every time!
I still have no idea why the GMail app doesn't work properly. I have the latest version of both the app & Android. But the default Email app syncs & notifies me perfectly.
I want to share this knowledge with everyone, and being my first post here and a VERY HAPPY Nexus 7 user, I hope this helps at least one person.