Nah, characters are cached only once, regardless if it was a request on main page, or from live guild report. The problem is that guild report shows character in best scored spec, and that spec might have some old cache.
Example:
Paladin has 4500 score in protection spec, last seen on Aug 1st in that spec.
His second spec (lets say holy) has score 4400, and in the last 2 weeks we only see him logging off in this spec, so we can't update his prot spec/gear. So on guild page, he will be shown as protection paladin, 4500 score, last cached 18 days ago.
I hope that I wasn't too confusing with all this. I have to admit that it might be better if we just show the latest cache date, regardless of spec.