When you put a 99 minute CD into your machine, and check the amount of data you can store the first thing you will see is that it is the same size as a regular one.
This is not true as these discs are set up to be overburnt, and this is something that software programs can't detect.
What you have to do is set up the software on your machine so it can Overburn the disc, and this will allow you to access the extra data.
Click on the link below to see a tutorial on exactly how to use the discs