This pretty much explains why current and legal log books are so important. Although a driver can also be placed Out Of Service for other issues as well, the most popular being improper brake adjustment. Pre and post trip inspections are vital and another reason I try to keep my truck clean. It's easier to spot something out of the norm.

http://www.landlinemag.com/todays_news/Daily/2010/Feb10/022210/022510-04.htm