Thanks Tricia! Odd about 44 being in stereo. I still had Checker open and sure enough it shows section 44 as stereo, but it never occurred to me to check the validation tab. Status always shows as "Failed" anyhow because of the 128kb in the file name and poems typically being too short to make it happy. I didn't intentionally change any settings and 45 was back to mono as were the two preceding files. I looked in the manual and found how easily to correct stereo to mono, but haven't yet found how to do the reverse. I imagine an errant click or two split the mono track into stereo, but what they were I haven't a clue.
"A small daily task, if it be really daily, will beat the labors of a spasmodic Hercules."