I know Shamus won't need this link, but the rest of us might if only to keep up with his bastardisms...
http://www.insultmonger.com/generators/index.htm
Please disregard the nekkid ladies, we are only interested in the insults please.
Because the files created with DVD Author GUI is only enough data to fill up half a disc...don't think in terms of hours (LP, SLP etc.) think in terms of size and bitrate.
If you go to any other forum that has no ties to Imgburn you will get the same answer to ditch the shit media you are using...so don't consider these to be all to biased of a source.
The best I could ever do was 13X and change...and since you can only achieve the higher speeds towards the outside of the disc the measurement is best taken in the amount of time it takes to burn the entire disc. This would give you the highest average speed and I haven't found that burning at higher speeds to give that much less in quality, only a slight difference.
Maybe someone has been tinkering with the settings?
I don't recall deleting any of the logs and I've only got 41 of them saved, do they overwrite each other at some point or did I inadvertently delete some...not that I need that many.