Description of problem:
In virt-manager, install a new guest, then customize the configuration, Select Add Hardware->Storage, select a vmdk format storage,choose as virtio type, format as vmdk, then finish and begin installation. Then error display:
Unable to complete install: 'internal error process exited while connecting to monitor: char device redirected to /dev/pts/3
qemu: 'vmdk' invalid format
'

Version-Release number of selected component (if applicable):
libvirt-0.9.1-1.el6.x86_64
virt-manager-0.8.6-4.el6.noarch

How reproducible:
Always

Steps to Reproduce:
1. Launch virt-manager,Create a new guest
2. Tick 'Customize configuration before install', click Finish
3. Divert to guest details page, Click Add Hardware->Storage, select a existing vmdk format storage,choose as virtio type, format as vmdk
4. Click Finish and Begin installation
  
Actual results:
An error will display:
Unable to complete install: 'internal error process exited while connecting to monitor: char device redirected to /dev/pts/3
qemu: 'vmdk' invalid format
'
Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 45, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/create.py", line 1622, in do_install
    guest.start_install(False, meter=meter)
  File "/usr/lib/python2.6/site-packages/virtinst/Guest.py", line 1193, in start_install
    start_xml, final_xml, is_initial)
  File "/usr/lib/python2.6/site-packages/virtinst/Guest.py", line 1252, in _create_guest
    dom = self.conn.createLinux(start_xml or final_xml, 0)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 1454, in createLinux
    if ret is None:raise libvirtError('virDomainCreateLinux() failed', conn=self)
libvirtError: internal error process exited while connecting to monitor: char device redirected to /dev/pts/3
qemu: 'vmdk' invalid format


Expected results:
Installation should success. Or if vmdk is not supported pls hide this option.

Additional info:

# tail -f /root/.virt-manager/virt-manager.log
...
[Fri, 03 Jun 2011 11:39:11 virt-manager 6363] DEBUG (Guest:1229) Generated boot XML: 
<domain type='kvm'>
  <name>http</name>
  <currentMemory>524288</currentMemory>
  <memory>524288</memory>
  <uuid>e96f0a2c-8d83-e468-b1dc-a6d708f3313b</uuid>
  <os>
    <type arch='x86_64'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/><apic/><pae/>
  </features>
  <clock offset="utc"/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <vcpu>1</vcpu>
  <devices>
    <emulator>/usr/libexec/qemu-kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='threads'/>
      <source file='/var/lib/libvirt/images/http.img'/>
      <target dev='vda' bus='virtio'/>
    </disk>
    <disk type='file' device='disk'>
      <driver name='qemu' type='vmdk' cache='none' io='threads'/>
      <source file='/var/lib/libvirt/images/a11.img'/>
      <target dev='vdb' bus='virtio'/>
    </disk>
    <interface type='network'>
      <source network='default'/>
      <mac address='52:54:00:21:fd:c2'/>
      <model type='virtio'/>
    </interface>
    <input type='tablet' bus='usb'/>
    <graphics type='vnc' port='-1'/>
    <console type='pty'/>
    <sound model='ich6'/>
    <video>
      <model type='cirrus'/>
    </video>
  </devices>
</domain>

[Fri, 03 Jun 2011 11:39:15 virt-manager 6363] DEBUG (Installer:359) Removing /var/lib/libvirt/boot/virtinst-vmlinuz.xFPIzA
[Fri, 03 Jun 2011 11:39:15 virt-manager 6363] DEBUG (Installer:359) Removing /var/lib/libvirt/boot/virtinst-initrd.img.6SYCOQ
[Fri, 03 Jun 2011 11:39:15 virt-manager 6363] DEBUG (error:66) dialog message: Unable to complete install: 'internal error process exited while connecting to monitor: char device redirected to /dev/pts/4
qemu: 'vmdk' invalid format
' : Unable to complete install: 'internal error process exited while connecting to monitor: char device redirected to /dev/pts/4
qemu: 'vmdk' invalid format
'
Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 45, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/create.py", line 1622, in do_install
    guest.start_install(False, meter=meter)
  File "/usr/lib/python2.6/site-packages/virtinst/Guest.py", line 1193, in start_install
    start_xml, final_xml, is_initial)
  File "/usr/lib/python2.6/site-packages/virtinst/Guest.py", line 1252, in _create_guest
    dom = self.conn.createLinux(start_xml or final_xml, 0)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 1454, in createLinux
    if ret is None:raise libvirtError('virDomainCreateLinux() failed', conn=self)
libvirtError: internal error process exited while connecting to monitor: char device redirected to /dev/pts/4
qemu: 'vmdk' invalid format