Panarms sound glitch? o_O

[NetNomad]

So I'm playing a half-TTF (GC PSO Plus) to gain 40k and push my RAmar to level 140 tonight... I get to the first room in Cave 3 and kill everything up to the pan arms. I figure I can't really put a dent in them, so I just try draining exp with the godhand until they split. Once they do, I switch to my Yas9k and start shooting at the two halves. But this time... well, they sounded odd. The orange one (I keep forgetting which one is which) didn't make any sound at all when hurt or killed... but the blue one sounded like a Nano Dragon. Erm, yeah... I'm not lying. >_> Its pain sound became the dying sound of a Nano Dragon, and its dying sound became the Nano Dragon's laser sound. I moved onto the next Pan Arms and got the same result. At this point I DC'd myself, lest I get FSODed if it tried to read from some weird area of the disc at the wrong time (I don't claim to know anything about PSO's code, but I've spent enough time around ROMs and emulators to know that when you're reading from the wrong area, crazy crap might happen).

I started over and went back to the same room (even after the dragon pushed me to lv140). I got the same results... I piped up and down again and once again, same result. I continued on to see if the Nano Dragons would sound any different, but nope... their usual sound effects seemed to be playing.

I stopped playing then and went back to the lobby, where I told a couple friends what happened. Apparently, one of them gets that all the time and it's nothing to worry about. But what causes this? They certainly didn't sound like that yesterday. o_O Is there any harm in it? Is there any way to fix it, or will I have a new reason to kill Pan Arms every time before they split now? :ermm:

[day]

:puzzled: These things happen because i get a random laser coming through the floor:puzzled:

[DH-Damage]

lol I had a forest battle music in cave 2 once.
still don't know how that could happen