An interesting problem cropped up here. We've resolved it, but I'm curious about the underlying issue. Perhaps someone has an insight:

In documents based on one custom template, the custom body text style had stopped showing spelling errors. The paragraph style's set-up parameters seemed to be fine. Trying various operations, I discovered that the style had somehow gotten a character style invisibly "inlaid," which, once removed from selected text (Ctrl+Spacebar), brought forth the wavy red line. However, neither importing the same style from a template in which the style was working properly, nor deleting the problem one and then importing the good one, worked. We ended up recreating the template from a similar one in which the style was working.

Anyone have ideas about the "mechanics" of this?