Row height using autofit, with no merged cells

My application results in rows of varying height, due to word-wrap on. When I
try to condense my worksheet using autofit, some rows seem to play ball,
where others (with similar text entries) want to stay oversize. No cells are
merged, and I have tried toggling autofit and realigning, but no luck. It
ends up either laboriously moving each rogue line in turn, or printing 12
million pages. Any ideas?
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D.Smith