I have found that with the order of articles displaying that if you have more than one article on the same day (date) and you are ordering by DATE then it will display the first one published at the top and the following ones below. To get past this I added ordering on the ID also. Although not optimal as ID's may be reused it does at least fix the problem in most cases.
So instead of just "Date DESC" put this in the SQL:
Sean's right - in MySQL at least, the backtick is used to differentiate MySQL keywords and table/column names. For example, ORDER is a MySQL keyword, but `ORDER` will make MySQL look for the 'ORDER' column.
It's handy when you have tables that uses columns such as 'order'.