mythweb problem

Hello, I am using mythweb from wheezy.

When I access to the mythweb page I get this error on the web:

Error
data directory is not writable by www-data. Please check permissions.

I set the permissions this way:

chown -R www-data:www-data /usr/share/mythtv/mythweb

On the apache2 error log I have this:

[Mon Oct 08 13:28:30 2012] [error] [client x.x.x.x] PHP Warning:
Unknown: function '0' not found or invalid function name in Unknown on
line 0

Is possible to fix this?

Thanks and best regards.

--
Josu Lazkano