Can't unset function with unusual names

[AnMaster]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: x86_64-pc-linux-gnu-gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -march=k8 -pipe -O2 -msse3
uname output: Linux tux 2.6.22-gentoo-r8 #1 Mon Oct 8 18:38:06 CEST 2007 x86_64 
AMD Sempron(tm) Processor 3300+ AuthenticAMD GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 3.2
Patch Level: 17
Release Status: release

Description:
        Some names may be valid function names but not valid variable names 
(for example: foo-bar, -foo.bar, foo+bar).
        It is possible to create a function named like that but it is 
impossible to unset that variable after.

        It should either be possible to unset these or it should be impossible 
to name functions like that (the latter would break many existing scripts, at 
least - isn't that unusual in a function name)

Repeat-By:
        $ .foo-bar() { echo test; }
        $ .foo-bar
        test
        $ unset .foo-bar
        bash: unset: `.foo-bar': not a valid identifier