Getting blank page on Yahoo smart business hosting

[eluser]eugentudorache[/eluser]
Hello ,

I'm having a small/huge problem when putting a site on a Yahoo small business hosting.
I'm getting a blank page.

Other facts:

I'm not allowed to put my .htaccess file because of Yahoo's hosting.
I've turned error logging on, after reading hundreds of posts online, it works but doesn't show any errors. (it logs 404 errors when I visit non existing pages)

I simply ran out of ideas.

Please help!