Bug#245192: Same here
> Did anyone else experience something similar?
Unfortunately yes. I ran into the same effects you did: xmms is just fine, ogg
under kde is, only mp3 under kde is not.
It's like an additional rythm, very disturbing. But I encountered a few other
disturbing effects: Some files sound very noisy, others sound like if you
played them with one of these horrible "volume enlagers" (which produce
horrible sound in loud parts of the track).
I have no arts-effects enabled and all these files played well with KDE 3.1.5
under (Beyond) Linux From Scratch.
System: Debian Sarge