PHP settings for existing oscommerce site conflict with WP settings

Help. I know nothing about PHP. But when I try to backup my WP database, using the WP-DBManager plugin, it tells me that I have two errors in my PHP settings:

Checking PHP Functions (passthru(), system() and exec()) …
passthru() disabled.
system() disabled.
exec() enabled.

Please Rectify The Error Highlighted In Red Before Proceeding On.

Then, when I got to the PHP settings panel at my host (Aruba.it), I see that the PHP.INI file customization is set to the radio button for oscommerce (“settings optimized for OsCommerce applications”) instead of wordpress (which is another option.

The problem is that the site is currently functioning as an oscommerce site, and I am setting up the wordpress site on a subdirectory until we switch over.

How can I correctly set up my WP to backup without messing up the current site?

Thanks for any replies! -Mariana