Supplier Site not getting Active

I am trying to activate an inactivated site in R12. I have made the site active in the 'Update' screen of Adress Book and trying to remove the 'End Date' from the 'Manage Site', however, the date field is greyed out. Another strange thing that I find is when I go to 'Quick Update' the site is showing under 'Inactive' heading where as under the address book it is showing as 'Current'. If i update the site name it still shows the old name in manage site screen.

Please help.

Thanks