ctrl+r + left cursor + multiline PS1 = wrong cursor displaying

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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   -O3 -march=pentium3 
-mfpmath=sse -mmmx -msse -momit-leaf-frame-pointer -fomit-frame-pointer -pipe 
-funit-at-a-time
uname output: Linux gentoo 2.6.17-co-0.8.0 #1 PREEMPT Fri Oct 6 04:51:48 UTC 
2006 i686 AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ AuthenticAMD GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 3.2
Patch Level: 15
Release Status: release

Description:
        when i done "Repeat-By" section, i got the "echo abcdefg" loaded as 
current input buffer
        i can press <left> or <right> multiple times to move the cursor, and or 
edit the input buffer
        expected: cursor moves in the range of "echo abc", and the beyond "c"
        actually: cursor moves in the range of "$ echo ab" (including b)
        this does not happen on older release (i forgot the version)

Repeat-By:
        $ PSCOLOR=36
        $ export PS1='\[\e['$PSCOLOR'm\]\u@\h \[\e[34m\]\w\n\$\[\e[0m\] '
        $ echo abcdefg
        $ <CTRL-r>
        (reverse-i-search)`': abc<left>