[plt-scheme] module->namespace and enter!

Hi,

In MzScheme, if i invoke module->namespace with a non-loaded module path
as argument, i got, as expected, an exception (even the file exists):

> (module->namespace '(file "/tmp/foo.ss"))
module->namespace: module not instantiated in the current namespace:
#<resolved-module-path:"/tmp/foo.ss">

So far so good. But if i subsequently enter! the module, in the first
place a i don't get the familiar [load...] messages:

> (enter! (file "/tmp/foo.ss"))
>

although i'm in the module's namespace alright, so that's not bad. But,
if i go back to the top level, modify foo.ss and re-enter! the modified
module, enter! does not notice the change, and does not reload foo.ss
My expectation is that it should (i'm not modifying any public binding,
but the behaviour is the same with compile-enforce-module-constants set
to #f), i.e., enter! should reload as needed.

Is this a bug, or are my expectations wrong? (I'm using a recent SVN
version, 4.2.4.4).

Thanks!
jao