To burn a DVD in Final Cut Pro X (FCPX) version 10.0.8 go to File > Share>DVD. A
small processing bar comes up for a short time and disappears. To see if it is processing, go to background task window in Window>Background Task, command 9 or click on the background processing window.
In this version compared to 10.0.4 the background task bar is the only indication that it is processing a DVD, which may lead to some confusion that it is actually processing.
It is easy to think the Share DVD command is not working because there is no visible progress bar. Wait until your Project is done rendering any changes before you go to Share DVD. Your processing time for the DVD will be improved.