Property Upgrade?

This is happening since yesterday..

When you go to your Homepage tab, you can see the UPGRADE button on the

BUILD YOUR EMPIRE module.

This button is available for four sections of Properties in New York ie Chop Shop, Weapons Depot, The Armory and the Private Zoo.

But the UPGRADE button only available for the ingame cross promotion items between Mafia Wars and FrontierVille-Cafe World games.

For the normal items, you can still see BUILD IT button, not the UPGRADE button.

Nothing happens when you click on the UPGRADE button. Since many of us has fully upgraded our Properties..

So, this is still a big question for us.

What's the use of the UPGRADE button?

It's just a temporary glitch? Why Zynga team keeps it for more than 1 day to fix it?

We can only wait then..