I always try to promote a sense of unity by displaying my St. Andrews Cross
(for the ignorant, that's the Confederate Stars and Bars)
Well OldCorp...that is news to me; and I am hardly ignorant My intent is not to put you down, but you are a little mistaken; please understand this is not meant to cause offense. Here's a little background on the Cross of St Andrew
I'm not a Scots national but I have a fair bit of Scots blood in me to go with my last name (Blair - or, 'a battlefeild' - they make a tolerable nice Scotch in the area of Blair Athol by the way). As you see, the crest of my family name features a "Saltyre" that looks a touch familiar to the Sons of the South
http://www.clanblair.org/cbshreld.html
Although the Saltyre (or "cross") can be used to describe most any flag with a cross on it, "St. Andrews's Cross" is in almost all cases associated with the Flag of Scotland, an entity a little older than the CSA.
The Flag of Scotland is called "St Andrew's Cross" because of a white cross seen against a blue sky, in reference to legend that holds a vision of St Andrew (who was crucified) appeared predicting victory to the Scots (who were at the time probably actually Picts) in battle. This was considered a divine Omen, and the white cross against the blue field representing the sky was adopted as the Scots Flag, literally representing the cross on which St Andrew died
http://www.britishflag.us/scotland.htm
I think it probable that the locality you're in uses that term because if you were able to track down the etymology - or 'word-history'- of the use of the term "St. Andrew's Cross" in the South, you'd find plenty of Scots living in the area, and the passing similarity to the Saltyre of St Andrews caused them to call the Battle Flag/Naval Ensign of the Confederacy that. Although the only similarity is really the white cross.
In other words, the "Cross of St. Andrews" is a term somebody or other borrowed in reference to the Battle Flag/Naval Ensign of the Confederacy, but in reality, it refers to the Scottish National Flag