When you install Microsoft Office SharePoint Server 2007 (MOSS 2007), out-of-the box the Contributor Settings will be enabled on your site(s). You will notice this in the SharePoint Designer task pane. By default your account will (probably?) be in the Content Authors group, wich may “restrict the use of some features” as the task pane mentions.
You can verify the permissions when you click the View your Contributor Settings, as you can see the SharePoint permissions (workflow, templates, etc) are disabled. Even worse, it seems that you can’t enable them!
To customize the Contributor Settings to your needs, you need to go to the Site menu and choose Contributor Settings. If you want to get rid of all the Contributor Settings, just click the Disable Contributor Settings button.