Several vB4 owners are having a problem where some members cannot post. It has not been completely narrowed down yet but some suspect that it is IE users on Vista with some settings, others are not so sure. vB at this point do not know the cause and in fact was not aware of this problem. We have our own ideas on what is causing this and are going to investigate the causes. It looks like vB dropped the ball for some users on the latest changes. You should be fine in Firefox. Here is what the screen will look like if you are one of the members affected.