I could never connect to FB when on wifi. Had to turn off wifi to get comments to load.
Uninstalled the FB app and started browsing to mobile site to post my comments, which works fine on both wifi or 3g.
I do a lot of browsing with Opera Mini as it is a lot faster to load webpages in Opera Mini than in Dolphin HD. Only time I use Dolphin is if I know the site has videos I want to watch. If I'm just reading and posting, Opera Mini is my default browser.