[plt-scheme] build-vector undefined in fresh DrScheme interactive window?

Hello,
I noticed that when I open a new tab in DrScheme, and input (for example):

	(build-vector 10 (lambda (x) (random 100)))

I get the error:

	reference to undefined identifier: build-vector

* Other vector related names that I , such as vector->values or 
vector-fill! seem to work.

* build-vector works in a fresh mzscheme REPL started from the 
command-line.

* build-vector starts working normally after running a program from 
the editor window that includes #lang scheme.

Is this a bug or expected behaviour (that happened to be unexpected to 
a newbie)?

I am running 3.99.0.12-svn14feb2008 [3m] on Windows XP atm. Language 
is set to Module in GUI.

Thanks,
--Yavuz

Incidentally, is it better to use the bug report form for these "small 
bug or maybe a 'feature'" type things or mail list?