"ignoredisk --only-use=sda" kickstart option NOT working on Red Hat Enterprise Linux 5

Issue

• Kickstart installation stopped with the following message in anaconda.log

  15:05:22 CRITICAL: parted exception: Error: Error opening /tmp/sdb: No medium found
  

• This server has the virtual floppy device and virtual cd device, which show up as /dev/sdb and /dev/sdc.

• If using 'ignoredisk --drives=sdb,sdc', the installation works fine.
• But, if using 'ignoredisk --only-use=sda', this problem occurs.
• --only-use= option is documented in http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/Installation_Guide/s1-kickstart2-options.html