Why it can't be possible to post on forum using phpbb, vbulletin via UltraSurf 9.96a, since the help said :

2. If I use UltraSurf to post on forums or visit web sites, does the forum or web site know my real IP?
A: No. UltraSurf uses advance proxy technology. It will hide your real IP from all websites.

Please post in this forum in Chinese, or not answer your question, thank you.