As instructed I have started my own topic, which I did not do originally to not create something potentially redundant.
The problem just started occurring since I just got around to upgrading to 2.4.2.0. I killed about 3 discs after I noticed that 1) when this happened I couldn't fully cancel out of ImgBurn (apparent crash) 2) my Liteon LH-20A1L kept blinking and wouldn't release the disc unless I rebooted and 3) the discs that were failures had a different amount of data on them despite failing at the same point. That last one got me thinking that the first two symptoms might indicate that the disc was actually still being burnt despite indications otherwise.
After this started I switched to Nero to check myself and was able to burn there fine.
Tonight I decided to try an experiment. I decided to let it go after the failure to see if the disc burnt. I got impatient after several minutes sitting on the first failure warning, and clicked retry, which I had tried with previous attempts but not after waiting a bit. This time it picked right up and completed the main track, but "failed" in the switch to the lead-out. I waited again, clicked retry, and the disc finished burning. Despite all of this, the disc verified okay! I don't know enough about the changeover from lead-in to main track to lead-out to know exactly what this means, but it definitely is strange. Below is my log. Some information has been obscured by asterisks intentionally.
I 19:03:34 ImgBurn Version 2.4.2.0 started!
I 19:03:34 Microsoft Windows XP Professional (5.1, Build 2600 : Service Pack 3)
I 19:03:34 Total Physical Memory: 3,144,108 KB - Available: 2,048,208 KB
W 19:03:34 AnyDVD can interfere with ImgBurn's ability to verify accurately, please ensure it's disabled!
I 19:03:34 Initialising SPTI...
I 19:03:34 Searching for SCSI / ATAPI devices...
I 19:03:34 Found 1 DVD-ROM and 1 DVD