Nah, I don't remember having any trouble with those.
...though I was still overly cautious with them anyway, because being overcareful is what I do at times.
Again it was an FOE in III. If I remember right (it's been a bit since then,) I misjudged my steps and ran into it, so the thing tore me to shreds. ^^" III definitely hates you more than IV does, that's for sure (though I haven't gotten that far in either, the former because of time, the latter because until today all I had was the demo, so I could be totally wrong too).
And... oh dear. We'll see how well I avoid getting being torn to shreds once I get to said sirens. ^^"