Does the middle page have a purpose?
 

Im refering to the page which says something like:

Im wondering if php is actually executed on the page, or if it is just there to give the user information about what happened, and wouldnt cause problems if it was removed.

Thanks for any help you can give,

James

In some cases i think it's used to set/reset cookie values.

AdminCP -> vBulletin Options -> Cookies and HTTP Header Options -> Remove Redirection Message Pages: Yes

Those that are not removed by this option are needed to ensure vBulletin will work correct.

Thank you. The ones i was most concerned with was the logging in page, and the message / reply posting page. Would it be difficult to modify the code so it doesnt require a new page, for example have a javascript popup that says thank you for posting a message and sets the cookies. Might that be possible? I know i could have problems when someone has javascript off, but im sure there could be a way of stepping down.

as marco suggested you can turn off redirects via vbulletin options ...
however, in some instances the redirect is required for one reason or another

when logging out the system temporarily "remembers" the page you were on so that it can redirect you back to the same page