False alarm! Found a old similiar post where it mention that a format would take 15 minutes. Sure enough, exactly 15 minutes later it finished the erasing and continued on. This is a new PC and my first with a DVD, although I've burned DVD+RW before, I don't remember the Format/Erase taking that long or maybe I just wasn't present to watch. From Windows, it doesn't take no where near 15 minutes to format.
The first time it takes a bit long time to format it correctly. The next time when you format with ImgBurn it will only take some seconds. Other programs do not really format the disc in a proper way, that's why they are faster.