Where is the php.ini file in Ubuntu hardy

From the INSTALL file in php-5.3.1.tar.gz:

13. Setup your php.ini file:

PHP will use the built-in default values if no php.ini file was
placed in the configuration directory. The default location is
/usr/local/lib, if you prefer your php.ini in another location, use 
--with-config-file-path=/some/path in step 10.

The PHP distribution provides two sample php.ini files, you can use them
by
  cp php.ini-development /usr/local/lib/php.ini
or
  cp php.ini-production  /usr/local/lib/php.ini

If you choose one of these php.ini files be certain to read the list
of changes within, as they affect how PHP behaves.

You need to create the php.ini file. This can be done by copying one of the sample files.

I had troubles getting FCGI and PHP to coexist peacefully with IIS6 on my server as well, although I had different problems. Based on what you posted from your fcgiext.ini file, it looks like you need slightly different configuration options, namely ExePath needs to be set instead of ext. Here's a snippet from the fcgiext.ini file on my production server hosting several dozen sites:

[Types]
php:633747741=PHP-TEST
php=PHP-Production

[PHP-Production]
ExePath="C:\Program Files\PHP-5.2.10-nts-vc6\php-cgi.exe"
EnvironmentVars=PHPRC:C:\Program Files\PHP-5.2.10-nts-vc6
InstanceMaxRequests=1000
ActivityTimeout=1200
RequestTimeout=1800
MaxInstances=100

[PHP-TEST]
ExePath="C:\Program Files\php-5.2.12-nts\php-cgi.exe"
EnvironmentVars=PHPRC:C:\Program Files\php-5.2.12-nts
InstanceMaxRequests=5
ActivityTimeout=1200
RequestTimeout=1800
MaxInstances=100

I have two different configurations of PHP defined (PHP-Production and PHP-TEST) and I have set the default configuration to be PHP-Production. I have specified for IIS site number 633747741 to use configuration PHP-TEST instead.