Current behaviour: The Potion of Perception's (POTN39.ITM) item description states that it confers a +20% bonus to Hide in Shadows, but it uses Opcode #59 (Move Silently Bonus).
Suggested behaviour: The Potion of Perception should use Opcode #275 (Hide in Shadows Bonus), instead.
Games affected: BG2, BGEE.
Notes: This bug is present in BG2, as well. Also, I noticed the BGEE version of POTN39 has a second ability header, directly inherited from BG1 (and nowhere to be found in the BG2 incarnation). I'm not sure what this ability is for, but one of its effects is to cause exploding death!