This drive depending on the firmware version, apparently doesn't support permanent bitsetting. That is, you have to change it each time.
So, here's an alternative:
1. Download and install imgburn:
http://www.imgburn.com/index.php?act=download
This is also a free program
2. Insert your Verbatim + R DL media in your burner.
3. Select your burner in the "Destination" drop down box.
4. Click "Tools"-->"Drive"-->"Change Booktype"
5. I believe your burner is really a Samsung SH-S182D. So choose Samsung.
6. Under "Change For:", select "dvd+r dl".
7. If your current setting is "dvd-rom", leave everything alone and exit Imgburn and stop following this list.
8. Under "New setting", select "dvd-rom". Click "Change" and then "Ok".
Exit Imgburn
Now, based on what I've read your burner will default back to its original setting each time you eject the drive. This means you have to do this each and everytime before you burn.
I hope this helps.