Microsoft Project DOES display a task split under the circumstances that you describe. The task split allows you to know that no work was performed on the task that week. But, if for some reason you do not want to see the task splits, then do this:
1. Apply the Gantt Chart view. 2. Click the Gantt Chart Format ribbon tab to display that ribbon. 3. In the Format section of the Gantt Chart Format ribbon, click the Layout button. 4. In the Layout dialog, deselect the Show bar splits checkbox. 5. Click the OK button.
You will need to set this option once per existing project. If you use templates from which to create your projects, you can deselect this option in your templates, which will eliminate your problem in all future projects. Hope this helps.