Command substitution reduce spaces even in strings

[matez]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: i686-pc-linux-gnu-gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib  
-DDEFAULT_PATH_VALUE='/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'
 -DSTANDARD_UTILS_PATH='/bin:/usr/bin:/sbin:/usr/sbin' 
-DSYS_BASHRC='/etc/bash/bashrc' -DSYS_BASH_LOGOUT='/etc/bash/bash_logout' 
-DNON_INTERACTIVE_LOGIN_SHELLS -DSSH_SOURCE_BASHRC -O2 -march=athlon-mp -pipe
uname output: Linux fiz15.jupiter.vein.hu 2.6.30-gentoo-r8 #1 SMP Thu Nov 12 
16:15:30 CET 2009 i686 AMD Athlon(tm) MP 2000+ AuthenticAMD GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 4.0
Patch Level: 35
Release Status: release

Description:
        [Detailed description of the problem, suggestion, or complaint.]

The command substitution reduce spaces even in strings.
This is not healthy on copying files of which names containing double or 
more spaces generated by command substitution.
Short example:

$ echo $(echo "'alfa  beta'")
'alfa beta'

Instead of 'alfa  beta' with double space.

Repeat-By:
        [Describe the sequence of events that causes the problem
        to occur.]


$ echo $(echo "'alfa  beta'")
'alfa beta'

Instead of 'alfa  beta' with double space.