[plt-scheme] possible enter!/drscheme bug

enter! is supposed to be provided in the scheme lang (though not  
scheme/base) right?

But in DrScheme, with #lang scheme in the definitions window, I get this:

Welcome to DrScheme, version 4.0.2.6-svn30jul2008 [3m].
Language: Module; memory limit: 128 megabytes.
> enter!
. . reference to an identifier before its definition: enter!
>

undefined?

hrm... further, if I instead load up mzscheme...

Welcome to MzScheme v4.0.2.6 [3m], Copyright (c) 2004-2008 PLT Scheme Inc.
> enter!
stdin::0: enter!: bad syntax; should be `(enter! <module-path-or-#f>)' in:  
enter
!

  === context ===
C:\Program Files\PLT\collects\scheme\private\misc.ss:68:7

>


so, MzScheme recognizes it.

Psy-Kosh