rbash and bash -r behave differently

[agriffis]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DSHELL -DHAVE_CONFIG_H  -I.  -I. -I./include -I./lib  
-mcpu=athlon-xp -O3 -pipe
uname output: Linux time.flatmonk.org 2.6.6-rc3 #1 Thu May 13 09:43:41 EDT 2004 
i686 AMD Athlon(tm) Processor AuthenticAMD GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 2.05b
Patch Level: 0
Release Status: release

Description:
        rbash and bash -r behave differently, but the man-page and
        info pages say they should be the same thing.  I'm not sure
        which behavior is actually *correct*

Repeat-By:
        PATH=/bin rbash         # reads startup files, including
                                # ~/.bashrc, and allows setting of
                                # environment variables

        PATH=/bin bash -r       # attempts to read startup files, but
                                # disallows setting of environment
                                # variables; spews error messages