By default in AutoCAD 2006, the DTEXT command works differently compared to earlier versions. It is now known as "In Place" DTEXT. To revert back to the old DTEXT, use the system variable called DTEXTED.
On the command line type: DTEXTED. Changed the system variable from the default 0 (zero) to 1 (one).
0 = Displays the In Place Editor
1= Displays the Edit Text dialogue box.