There is sort of an urban legend about writing the DVD at the slowest rate possible.
I have had many issues with discs burned at high speeds. Especially Audio CDs. They will not work in many CD players unless I burn them at a slow rate. This is more evident in the car or portable players. Also, some DVD Videos have had "Compatibility" issues with some players unless they have been burned at slower speeds.

Here is my simplified theory on the issue. To write a disc, especially a RW disc, the laser "Burns" a "pit" into the disc. If the pits are well defined and accurately placed, they can be read accurately. As the disc rotates faster, the amount of time the laser has to make a well defined mark, during the burning process, is shortened substantially. In short, the laser has difficulty making well defined pits in a shorter amount of time. That causes read errors, especially on RW media, since it is more difficult to make a well defined pit on the RW disc. Some media is more laser sensitive than others and some drives are better regulated for laser intensity on various media. That allows some drives to write on certain media at higher speeds. The obvious solution to the issue is to burn the discs at a slower speed to ensure that the pits are well defined and accurately placed, and not take the chance that their combination of drive and media are well matched for higher speeds.

Now the other side of the equation. The drives that are used to read the discs can have issues reading those pits as well. Some drives are better at reading poorly defined or placed pits than others. That explains why some drives are better at reading a disc that some others have failed to read or recognize.

Sometmes a firmware update can help eliminate some of these issues on the burn side or the read side of the equation and sometimes both.

There are other parts to the puzzle, such as media dye types and colors, recording layer reflectivity, etc., but that is my basic theory of why a disc should be burned at a slower rate for best results and compatibility.