capi:title-pane not updating

I create a simple interface, restricted in size, with a capi:title-pane displaying a text. When trying to change the text to a text that doesn't fit in the interface, the title-pane won't update (see listener excerpt below)

I would expect to see the text truncated.

I am using LW6 on Mac OS X 10.5 by the way.

Am I missing something or is this a bug?

Thanks!

/Sven

Listener excerpt:

NOTES

The title-pane text is updated nicely in 4, but not in 6.

In both cases the title-pan returns the updated text.

1 > (capi:define-interface test-panel () ()

(:panes

(title capi:title-pane

:accessor title

:text "short text"))

(:layouts

(main-layout capi:column-layout

'(title)))

(:default-initargs

:min-width 100

:max-width 100

:min-height 100

:max-height 100))

TEST-PANEL

2 > (setf tp (capi:display (make-instance 'test-panel)))

#<TEST-PANEL "Untitled LispWorks Interface - 8" 23FC6173>

3 > (capi:title-pane-text (title tp))

"short text"

4 > (setf (capi:title-pane-text (title tp)) "a longer text")

"a longer text"

5 > (capi:title-pane-text (title tp))

"a longer text"

6 > (setf (capi:title-pane-text (title tp)) "an even longer text")

"an even longer text"

7 > (capi:title-pane-text (title tp))

"an even longer text"