Warning for existing computer name doesn't disappear when the name is changed

[Otus]

To reproduce:

1) Have another computer on the network with e.g. the name 'abcd'.
2) Type 'abcd' as the name in the installer, it correctly warns.
3) Add some letters to get the valid name 'abcdefgh', it still warns.
4) Edit your name, now the warning disappears.

This is with the beta iso testing image 20110831.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: ubiquity 2.7.24
ProcVersionSignature: Ubuntu 3.0.0-9.15-generic 3.0.3
Uname: Linux 3.0.0-9-generic x86_64
Architecture: amd64
CasperVersion: 1.280
Date: Wed Aug 31 11:51:57 2011
LiveMediaBuild: Ubuntu 11.10 "Oneiric Ocelot" - Beta amd64 (20110831)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)