SiteCake cannot work without the url rewrite support. It is a mechanism that the web server itself implements - in this case Apache with the mod_rewrite module.
The url rewrite process (per user, in a mass hosting service - the standard case with hosting providers) is controlled by .htaccess file located in the web root folder. This apache config file is controlled by the user itself.
SiteCake deployment archive contains .htaccess file with the configuration options set as needed and tailored for the most common/standard case. However, each hosting provider can imply different configuration settings. So, if the SiteCake's test procedure fails with the 'URL rewrite support does not work correctly' message, you have to check the provider's documentation related to the url rewrite support.
By the way, 'urlrewriteTest' GET parameter is being set through the url rewriting process. You might take a look at .htaccess file.
