So I have been using the shortcut keys ctrl+E,C to comment markup code and ctrl+E,U to subsequently uncomment markup. What I have just realised is, that it works with code, but my expectations were not correct.
In code I would use the /* ... */ syntax for multiple line comments, but if you use the short cut on multiple lines of code, it uses single line comments.... for each line of code.
Still handy and a nice little short cut though <s>
Cheers
Andrew