lock order reversal

Hi!
I'm running the FreeBSD 5.0-RELEASE. When I boot up, this appears:

1st 0xc12a7230 process lock (process lock) _at_ ../../../kern/kern_descrip.c:2112
lock order reversal
I haven't noticed any disfunctions, but what does this mean?

I get a similar error when I use my soundcard:

lock order reversal
 1st 0xc120a680 pcm0 (sound softc) _at_ ../../../dev/sound/isa/mss.c:177
 2nd 0xc120a740 pcm0:play:0 (pcm channel) _at_ 
../../../dev/sound/pcm/channel.c:441

I have to restart the KDE artsd before the soundcard works correct. Please 
give me advice how to solve this.

Thanks in advance, Georg Funk