Here's a nifty trick I learned on another site. Creat a new text file and paste in it everthing between the dotted lines
[HKEY_CURRENT_USER\Software\ahead\Nero - Burning Rom\Recorder]
Save it and rename it nero.reg
Double-click it, and it will write a key into your Windows registry that sets Nero to read the ACTUAL speed instead of a set burn speed.
Some other apps, DVD Decrypter is one, are programmed to tell you the actual burn speed by default.