I'm having this problem also on Ubuntu64 'gutsy'. I have PulseAudio-0.9.6-1ubuntu-2 installed and configured. I've had one audio problem after another with Ubuntu.

I installed PulseAudio originally to solve a problem I was having getting flash audio to work in firefox, and PulseAudio solved that problem and has been working fairly smoothly except I can't seem to record audio.

In Sound Preferences > Devices I have 

Sound Events
  Sound Playback | PulseAudio Sound Server |  Test  *** works OK

Music and Movies
  Sound Playback | PulseAudio Sound Server |  Test  *** works OK

Audio Conferencing
  Sound Playback | PulseAudio Sound Server |  Test  *** works OK
  Sound Capture  | PulseAudio Sound Server |  Test  *** Pops up error message:

"Failed to construct test pipeline for 'gconfaudiosrc ! audioconvert ! audioresample ! gconfaudiosink profile=chat'"

And I can't seem to record anything. Microphone, etc. is un-muted.

I'm running the rt kernel  2.6.22-14-rt

lspci -v
02:01.0 Multimedia audio controller: Ensoniq ES1370 [AudioPCI] (rev 01)
        Subsystem: Unknown device 4942:4c4c
        Flags: bus master, slow devsel, latency 64, IRQ 21
        I/O ports at df00 [size=64]

both ~/.asoundrc  and /etc/asound.conf have:

----------------------
# Part I directly from ALSA Dmix Wiki

pcm.crbell { # crbell is my name, you can use your name, just make sure you use it below too
    type dmix
    ipc_key 1024
    slave {
        pcm "hw:0,0"     
        period_time 0
        period_size 1024
        buffer_size 8192
       #format "S32_LE"
       #periods 128
        rate 44100
    }
}

pcm.dsp0 {
    type plug
    slave.pcm "crbell"
}

# This following device can fool some applications into using pulseaudio
pcm.dsp1 {
    type plug
    slave.pcm "pulse"
}

ctl.mixer0 {
    type hw
    card 0
} 

# Part II directly from Pulseaudio Wiki

pcm.pulse {
    type pulse
}

ctl.pulse {
    type pulse
}

pcm.!default {
    type pulse
}

ctl.!default {
    type pulse
}
-----------------------------------

Also, although with KMid I can play MIDI out through my attached external yamaha synth, I can't seem get MIDI in from it.

In /etc/modprobe.d/alsa-base  I see:

------------------------------------
# autoloader aliases
install sound-slot-0 /sbin/modprobe snd-card-0
install sound-slot-1 /sbin/modprobe snd-card-1
install sound-slot-2 /sbin/modprobe snd-card-2
install sound-slot-3 /sbin/modprobe snd-card-3
install sound-slot-4 /sbin/modprobe snd-card-4
install sound-slot-5 /sbin/modprobe snd-card-5
install sound-slot-6 /sbin/modprobe snd-card-6
install sound-slot-7 /sbin/modprobe snd-card-7

# Cause optional modules to be loaded above generic modules
install snd /sbin/modprobe --ignore-install snd && { /sbin/modprobe --quiet snd-ioctl32 ; : ; }
install snd-pcm /sbin/modprobe --ignore-install snd-pcm && { /sbin/modprobe --quiet snd-pcm-oss ; : ; }
install snd-mixer /sbin/modprobe --ignore-install snd-mixer && { /sbin/modprobe --quiet snd-mixer-oss ; : ; }
install snd-seq /sbin/modprobe --ignore-install snd-seq && { /sbin/modprobe --quiet snd-seq-midi ; /sbin/modprobe --quiet snd-seq-oss ; : ; }
install snd-rawmidi /sbin/modprobe --ignore-install snd-rawmidi && { /sbin/modprobe --quiet snd-seq-midi ; : ; }
# Cause optional modules to be loaded above sound card driver modules
install snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 $CMDLINE_OPTS && { /sbin/modprobe -Qb snd-emu10k1-synth ; }
install snd-via82xx /sbin/modprobe --ignore-install snd-via82xx $CMDLINE_OPTS && { /sbin/modprobe -Qb snd-seq ; }

# Load saa7134-alsa instead of saa7134 (which gets dragged in by it anyway)
install saa7134 /sbin/modprobe --ignore-install saa7134 $CMDLINE_OPTS && { /sbin/modprobe -Qb saa7134-alsa ; : ; }

# Load snd-seq for devices that don't have hardware midi;
#   Ubuntu #26283, #43682, #56005; works around Ubuntu #34831 for
#   non-Creative Labs PCI hardware
install snd /sbin/modprobe --ignore-install snd && { /sbin/modprobe -Qb snd-seq ; }
# Prevent abnormal drivers from grabbing index 0
options snd-bt87x index=-2
options cx88-alsa index=-2
options saa7134-alsa index=-2
options snd-atiixp-modem index=-2
options snd-intel8x0m index=-2
options snd-via82xx-modem index=-2
options snd-usb-audio index=-2
options snd-usb-usx2y index=-2
options snd-usb-caiaq index=-2
# Ubuntu #62691, enable MPU for snd-cmipci
options snd-cmipci mpu_port=0x330 fm_port=0x388
-----------------------------

Also, there are several audio apps that I really need for audio production that require JACK, and unfortunately, the Ubuntu pulseaudio packagers chose to remove the pulseaudio-module-jack modules!
If anyone has built the pulseaudio-module-jack package for JACK modules support for the Gutsy64 version of PulseAudio, I'd sure appreciate info on where I might find them. 

So, I'm unable to record audio or input MIDI or run JACK (without killing PulseAudio and reconfiguring everything). 

Any help appreciated.