For some reason I cannot pan any views when I press the middle mouse button (in any viewport), even using SPACE + MMB it does not work. Please can someone help or have a suggestion because this is driving me crazy

What operating system are you using - Linux, OSX or Windows? Hard to give suggestions without knowing that first

If you place down a node and click it with the mmb, does a box of info come up?

If not, is your MMB acting like a MMB? If you're on windows, you should try going to your windows control panel and looking at how your mouse is set-up.

All sorted, turns out is was just a software conflict with Logitech and Vista. Many thanks for the replies.

All sorted, turns out is was just a software conflict with Logitech and Vista. Many thanks for the replies.