We uploaded a logo, now we are trying to upload a different one. We delete the old one, then upload a new one and the old one keeps appearing.

Ahh...don't worry about that. The new one is there, but the old one is cached on your computer. After you upload it, just go to the main page and click reload a few times and it should show up just fine.

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The day Microsoft makes a product that doesn't suck is the day they make a vacuum cleaner.