Those are good ideas. I'll try them.

I'm starting to wonder if some sort of caching is affecting this. I had installed Ubercart package to the root of the public_html directory. Now, I moved all of these files to the uc directory and put just a simple index.html file in instead. But putting www.mydomain.com in the browser gives the same error as above.

Do you know if there is a cache that needs to be cleared? Thank you for your help!