Earlier this evening I saw a question in my 'Favorite Tags' view that sounded like it might have an interesting answer, and that said it was from 11 hours ago:

So I decided to have a look. Once there, I decided to make a few corrections. Only, after saving the change, I had a closer look at the question, and realised that:

• It was asked on Nov 9 2010
• Its answer was added on Mar 24, 2011 - and was edited on Jul 1 2011

That is, there were no visible changes on the page from anything close to 11 hours ago.

Possibly relevant info:

• This isn't a new problem: I typically notice it several times a day: this time, curiosity just got the better of me...
• I'm using Safari on an iOS 5 iPad. I think it happened before the upgrade to iOS, but can't say for sure.
• I have seen reports of problems with out-of-date cached pages on iPads since iOS5, but I don't believe I used the Back button in this case.

So, why did this just show up as 11 hours ago on 'Favorite Tags'?