Fortunately I have now solved the above issue.
Having searched a whole host of forums yesterday I found the embarrassingly simple solution. It turns out that because the car was locked and alarmed when the battery died, it remained in this state. Therefore, as soon as I reconnected the battery, it saw that the doors and bonnet were up and set of the alarm.
All I needed to do to overcome this was simply walk round and turn key in the driver's side door and, hey presto, jobs a good 'un.
I hope this may help someone else in the future,
H
Henry
March 2010