[Natty] Bash completion fails sometimes if filename contains with spaces

Binary package hint: bash-completion

I recently upgraded from Maverick to Natty, and am encountering the following problem with bash-completion:

Suggest there is a a directory or a file "test test".
Then, entering
~$ ls tes<TAB>
will result in
~$ ls test test
but it should be
~$ ls test\ test

The same occurs for other commands like rm.
But if there is a directory with this name, autocompletion works for the cd command (but not for other commands like ls and rmdir).

The following works:
~$ ls "tes<TAB>
This results in
~$ ls "test test"

Versions:
Ubuntu Natty 11.04 (development branch)
bash 4.1-2ubuntu5
bash-completion 1:1.3-1ubuntu1

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: bash-completion 1:1.3-1ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-3.30-generic-pae 2.6.38-rc4
Uname: Linux 2.6.38-3-generic-pae i686
Architecture: i386
Date: Mon Feb 14 16:54:55 2011
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=de_DE:en
 LANG=de_DE.UTF-8
 LC_MESSAGES=de_DE.utf8
 SHELL=/bin/bash
SourcePackage: bash-completion