I've got a custom animated .mdl, one sequence has a number 5004 event to emit a sound at a certain frame. It works well in HLAM and ingame, but when I save the game and then load, the sound gets played repeatedly (and annoyingly) every frame. Only way to unstuck it is to run the sequence again. Saving and loading again gets me the error once more. This only happens if the sequence has been triggered at least once before saving, nothing happens otherwise (as it should). I've read somewhere that 5xxx events are for weapon viewmodels only but that's not accurate I think.
I seem to recall that this was a common HL engine bug many years ago but it got fixed... Right?