http://lmgtfy.com/?q=padawan
You can use DVDInfoPro or Opti Drive Control to perform a quality scan, provided that your burner supports doing it.
As for where the blanks were made, it's printed on the spindle/box/packaging.
The DH4B1S burner is having communication problems: look for updated drivers for the motherboard's chipset or SATA controller where the drive is connected to. You might also want to try another SATA cable too. If it still gives this error try what this post from the FAQ says.
As for the HP burner it doesn't seem to properly support that media (e.g. 2.4x isn't a valid speed for the DVD-R standard). Try this firmware update to see if it helps. You could also try burning at 4x or 8x and maybe running a lens cleaning disc on that drive.
Media that doesn't work on three quite different burners tells us a lot about its quality, doesn't it?
All current Pioneer burners seem good. Since your drive is a SATA model then maybe you should get a Pioneer 215/216/217 (11x models are IDE interface and 21x are SATA interface)
Update your burner's firmware (remove any disc and close the tray before updating then reboot after it's finished). You can try a Full Erase on the disc to see if it gets better.
Use the Preview button, young padawan, and select the layerbreak where a small pause would be less noticeable (fade-in/out/scene change/etc). Also some players like better when the % is near 50/50 value.
Sounds like an UAC issue: when ImgBurn is run from the installer, it's run as an Administrator. If you right-click ImgBurn's shortcut and choose Run as Administrator, does it work as it should?
Update ImgBurn.
Your USB chipset and USB enclosure aren't playing nice with each other, so search this forum for semaphore timeout to find what you can try in order to solve this problem.
Are you plugging it directly to the computer (i.e. no USB hubs or anything)? Try on the USB ports at the back of the computer. Also look for an updated USB driver for your USB chipset (you can use SIW to find out which one you have).
You should also install Service Pack 3.
Use the Verify mode to check the disc against the source image, and next time leave Verify enabled, as that's what ensures the burn was good or not (miscompare/error = bad burn).
Well, the log doesn't show any disc being burned nor verified, which is what would tell us if the burn was good or not. As for the video being PAL you need to check your devices to see if they support it.
When it hung, did you close ImgBurn? Do you have a log from that burn? Look in ImgBurn's Help menu.
As for the unable to lock it's covered in the FAQ thread.
Close all unneeded programs, remove any disc from the drive, close the tray and run the 1.06 firmware updater: it'll find your drive and then you click the update button. That's it.