Why are my trombones out of tune?

[passagio]

On several occasions, my trombone - usually assigned to the tenor voice - suddenly plays out of tune. It doesn't matter which trombone player I use, solo, AG, Player 1 etc. Initially, this voice plays correctly, today however, I made myself lunch, and when I came back my playback file is unusable.

Finale 2010
GPO 4 (full)
Aria player

[Haydn]

Have you recorded some pitch bend info by any chance?

Jim

[passagio]

Oddly, it turns out that the measure to left on my screen, in whatever voice was active, transposed down a half step on save.... trés stránge.