You're eight or nine percent body fat and still feature a gut?
I think the answer might not be cardio or diet.  Instead, the 
abdominal wall might be weak.  That is, the muscles are not 
tightly held together.  The result is a distended look -- and a
greater susceptibility to hernia.
Ultimately, you might be a good candidate for abdominoplasty.
The procedure is like a nose-job for the stomach.  It involves a
restitching of the muscles discussed above.  Think about it.