Blank page debug also blank!

Hello,
I am attempting to install zen cart 1.3.8a on an Earthlink Hosted server for a client of mine: http://www.adultdaycc.org/zencart

When I try to go to the install page for the first time, I get a blank page. I uploaded the debugging utility mentioned in this forum, but the log files do not seem to be generated.

I have checked the permissions several times.

I want to try to solve this on my end, as earthlink support usually concludes their unhelpful guesses with the suggestion that my client buy their built in cart software, which is not an option.

One thing is that they are running php5.0, and require all php files to be named .php5 . Since I don't want to rename ALL application files, I have a line in the .htaccess file to run all files as php. I copied the line directly from the earthlink support site, and it did change the display from code view to the blank page, so I guess it's working...

Assuming that switching hosts is not possible, can anyone suggest my next step?

Thank you,
Julia