Yahoo Installation Problem

Hi,

I just purchased a yahoo small business hosting account to transfer my wordpress blog to.

What i did was installed a brand new installation of wordpress in my ROOT directory, then upload/overwrite all of my already existing files, then imported the .SQL database via phpMyAdmin, overwriting the clean installation.

Then, when i pointed my browser to the temporary URL Yahoo gave me, I got this error:

Sorry, the page you requested was not found.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

Please check the URL for proper spelling and capitalization. If you’re having trouble locating a destination on Yahoo!, try visiting the Yahoo! home page or look through a list of Yahoo!’s online services. Also, you may find what you’re looking for if you try searching below.

I called Yahoo technical support and they said I needed to point my old domain to the Yahoo server. But I dont understand why i can’t just use the tempory URL they gave me.

Can someone tell me if they are right? I dont want to switch over the DNS until i’m positive WordPress is working fine with my database before it goes live.

Thanks!