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Going by the manual, the DVD-R V (Video) mode should be compatible with other players, so a few likely issues may include disc quality issues or compatibility issues with the recording mode. As standalone DVD recorders physically write to disc much slower than a PC and do so intermittently as they can only write in real time, a disc that may work fine in a PC optical drive may not be of good enough quality for the DVD recorder. I’ve had this issue happen on me a few times in the past where the title shows, but will go no further with a few brands of discs.
To start off with, if you have a large quantity of these discs left, I would suggest trying a different recording mode (e.g. SP) just in case it is related to how the player handles the recording mode. It’s unlikely the issue, but worth a try to start with.
Otherwise, try a different brand of DVD-R, such as Verbatim (assuming you’ve not tried this brand). If you’ve already tried a few DVD-R brands, try a DVD-RW, first in the DVD-R V mode and also in the VR mode to see if either of these helps. DVD-RW also has the advantage in that you can erase it later, such as if you recorded a wrong program or it was not shown, etc. You can then later transfer the DVD-RW recordings to DVD-R on a PC for permanent store and to reuse the more expensive DVD-RWs for new recordings.