Anyone else having to log in every few hours?  Why is site kicking me out so often?

No, not seeing that here.

Did you change any settings in your browser that would cause it to delete cookies every time you close it, or are you using "in private" mode?

Every time Firefox updates, I have to sign in again.

It's probably a browser setting.  On my laptop, I'll let the site remember me because I'm the only one that uses it.  On our family desktop, I have the browser set not to remember because I don't want anyone else having access to my account.

If I am inactive, say I'm typing a lengthy email or writing a review I always have to log back in.

I have not been seeing any unusual behavior tonight regarding getting kicked out and having to log back in.  I do continue to get logged out after relatively long periods of inactivity (say, 15 or 20 minutes or so), but this is normal in my experience.