Yep I am facing this problem as well since upgrade. Actually, whenever we post using quick reply method....and next time we visit the post, I loads the cache only. Just reload the page and u will see the post. A nasty bug of vbulletin....it seems.....maybe the problem is only with Opera.
heh IPB never had cool linking structure. one of the primary reason i ditched it. now, i had wished if opera had site specific setting for caching. it does not currently. so you would have to change the settings for entire browser which i know would not be something you had like.