I keep unticking (work offline) in the tool dropdown box on my laptop but it keeps coming back on again. How can I stop it reappearing all the time?

Laptop, eh? Maybe your laptop is disabling the connection to save on power. You can disable that if that is the case.

Click on START > MY NETWORK PLACES
Rightclick your connection and select Properties
In the Connect Using: box you will see your network card...click on CONFIGURE...
Your network card driver menu will appear, click on the Power Management tab
Untick the Allow computer to turn off this device to save power
Click OK
Hope that does the trick!

Edit: If you're using internet explorer, go to Tools > Connections > LAN settings and check Automatically Detect Settings.