With DAT Power, you have the capability to delete all of your postings at one time. However, if you have a lot of postings, enough to where you have to scroll to see them all, DAT Power may not highlight all postings at one time when the box is checked. This is due to the fact that DAT Power does not load all of your postings into the browser until you need them, which you indicate by scrolling down to see them.
To ensure that you select all of your postings, you must first scroll to the bottom of the list to ensure that all of them are loaded into your screen. Once you have done this, you can select the check all box and delete all of your postings at one time.