Can't install the Module - Fata error to undefined function

I'm getting this too!
Fatal error: Call to undefined function system_schema() in /sites/all/modules/stc_taxes/stc_taxes.install on line 206

Drupal: 6.14
Ubercart: 6.x-2.0

I did some research on this problem and applied the fix found at:

http://drupal.org/node/634556

It looks like the method used to get the schema is different in the fixed version. For posterity, here is the code:

/modules/stc_taxes/stc_taxes.install line 213:

<?php
  $system_module_schema = system_schema();
  $tables['cache_so_tax_rates'] = $system_module_schema['cache'];
?>

Should be:

<?php
  $tables['cache_so_tax_rates'] = drupal_get_schema_unprocessed('system', 'cache');
?>

The module would then install properly. I did not test its functionality, but the drupal path:

/admin/store/settings/stc_taxes

displays what I would expect.