What version of Epic are you using? There's a bug in Epic 5.1 that disables certain PIs. We received a special patch, but it might also be fixed in patch C. If you just moved to 5.1 and these are PIs that previously worked, that might be the problem.
If the savetext/usetext case is causing the behavior, it should be possible within the entities to replace the _newline PIs with a tag (preferably an empty, singleton tag) of your choosing or invention. The e-i-c for this tag could then have the appropriate textbreak properties. This would have to be *real* tag from your DTD, not a pseudo-tag. If you don't have control of your DTD, this might be a problem. I have not tested this, so I do not know if it works. If it does work, then it should be easy to write some ACL to replace the PIs, or just use a text editor and search/replace within the entities.