[Seaside] Lightbox in child component

[Amos]

Hi all,

I was trying to write a small Seaside application and wanted to try
using a lightbox to display an error message (say when logging in with
an invalid password). In my case, the call to #lightbox: seemed to do
nothing at all (except refresh the page; 3.10.6 image), yet when I
tried the lightbox test (from http://localhost:8080/seaside/ -> tests
link -> lightbox-dialog link), it worked just fine.

Investigating this a bit further to eliminate possible differences, I
ended up embedding SULightboxTest itself into my application, and
found that it doesn't work there... my guess is that it only works as
a standalone component, not as an embedded child component. (Can
anyone confirm this?) Even trying to provide the child with a parent
reference (the root component) and then calling something like:

self parent lightbox: (WAFormDialog new
    addMessage: 'testing...';
    yourself)

does nothing (the code is executed, but I don't yet know enough about
AnswerContinuation, WARenderNotification, et al to be able to tell
where it's going "wrong").

Am I missing something really basic, could it be something in my
image, or is this a general problem?

Cheers and Happy New Year,

Amos