Just found this on NicWs' forum.
I believe this may be your issue.
Update your version of DVDInfoPro!
I am a bit lost here. I have NEC 2500A writer and Samsung dvd-rom drive. Whenever I use Nero CD/DVD Speed it reports speed up to 8x while reading data dvds on both drives. DVDInfoPro on the other hand seems to be locked at max 2x. I have no idea why. I've checked my PC settings, all seems normal, i.e. Ultra DMA 2 etc. BTW, I running Win XP. Any idea why ?
This is a known problem and occurred between versions 2.30 and 2.33 inclusive, please update to the latest version and the problem will be gone.