An issue with formatting of the Grand Total Labels was just brought to my attention and I thought I should bring it to everyone's attention just in case they want to format Grand Totals. This is a particular nasty issue that you really don't want to run into. The good news is that if you format things in the right order you will not have the problem. I have prepared a video to show you the issue and how to get around it.
This has been brought to the attention of Oracle support and a bug # 11772408 has been assigned. I hope there is a fix soon.