Thanks for the new info. My hobby is researching and documenting Confederate graves in the state of Georgia. I happened upon the James Ellison Warren grave on the Find-A-Grave site (See my previous post to Alan Pitts) and was confused on the 115th Alabama Regiment which I thought was an error. I have found all sorts of mistakes on VA markers, so yours was nothing unusual.
No need to bother with sending my any more info on him. Now that you have enlightened me, I now know for sure his correct unit.