I'm getting similar messages:

Feb 17 23:49:39 multi pulseaudio[3075]: ratelimit.c: 16 events suppressed
Feb 17 23:53:12 multi pulseaudio[3075]: ratelimit.c: 16 events suppressed
Feb 17 23:53:17 multi pulseaudio[3075]: ratelimit.c: 16 events suppressed
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c: snd_pcm_avail() gibt einen Wert zurück, welche außerordentlich groß ist: 18446744073709524840 bytes (384307168062 ms).
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c: Dies ist wahrscheinlich ein Fehler im ALSA-Treiber 'snd_hda_intel'. Bitte melden Sie diesen Punkt den ALSA-Entwicklern.
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c: snd_pcm_dump():
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c: Hooks PCM
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c: Its setup is:
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   stream       : PLAYBACK
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   access       : MMAP_INTERLEAVED
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   format       : S16_LE
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   subformat    : STD
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   channels     : 2
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   rate         : 48000
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   exact rate   : 48000 (48000/1)
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   msbits       : 16
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   buffer_size  : 16384
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_size  : 8192
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_time  : 170666
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   tstamp_mode  : ENABLE
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_step  : 1
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   avail_min    : 12545
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_event : 0
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   start_threshold  : -1
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   stop_threshold   : 4611686018427387904
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   silence_threshold: 0
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   silence_size : 0
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   boundary     : 4611686018427387904
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c: Slave: Hardware PCM card 1 'HDA ATI HDMI' device 3 subdevice 0
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c: Its setup is:
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   stream       : PLAYBACK
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   access       : MMAP_INTERLEAVED
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   format       : S16_LE
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   subformat    : STD
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   channels     : 2
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   rate         : 48000
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   exact rate   : 48000 (48000/1)
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   msbits       : 16
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   buffer_size  : 16384
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_size  : 8192
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_time  : 170666
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   tstamp_mode  : ENABLE
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_step  : 1
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   avail_min    : 12545
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   period_event : 0
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   start_threshold  : -1
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   stop_threshold   : 4611686018427387904
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   silence_threshold: 0
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   silence_size : 0
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   boundary     : 4611686018427387904
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   appl_ptr     : 39476
Feb 17 23:53:18 multi pulseaudio[3075]: alsa-util.c:   hw_ptr       : 16398
... and these messages very often repeated

PulseAudio consumes 100% of one CPU then.

System is:
Acer Aspire L5100 with HDA-Intel
Ubuntu 9.10 (karmic), Kernel 2.6.31-19-generic
GCC version: 4.4.1 (x86_64-linux-gnu)

SW-Versions:
ALSA-Base: 1.0.20+dfsg-1ubuntu5
PulseAudio: 1:0.9.19-0ubuntu4.1