Probaly stating the obvious here, but the problem with the pages only loading 5 posts or so... it seems to just stop the transfer of data (html) at a random point. Sometimes this point will be before the closing bracket ... > .... of an html line, hence the line of code appearing at the bottom of ones screen.
Could it be a server issue where it decides to cut off transmission of data randomly... there is a name for it but I cant remember.... connection reset by peer? *shrug*.
Whether thats caused by vbulltin or the server.. who knows?
back to work...