Prior to 7.1, if I placed my cursor anywhere inside a comment block "/* ... */" and executed "Selection uncomment" it used to find and remove the comment delimiters. Now this only works if you highlight the entire comment block first.
Try this ... open a package body and in the code content window right click and select comment. Then go into the editor and place your cursor in the newly commented code and select uncomment; nothing will happen unless you are on the very first line of the comment block ... I'm pretty sure it used to work from anywhere in the comment block.