YUI widget "Dialog" now depends on "Button Control"

Environment: YUI 2.3, IE 7.0

This is another problem I discovered during update from YUI 0.12 to YUI 2.3. As always, when updating library, there are many surprises that you have to run into.

Problem: Error message: "Error: Function expected" appears when I call the "render" method of YUI "Dialog" control a second time on the web page. Turn out the offending line is here: container.js, line: 6373,

if (oButton instanceof YAHOO.widget.Button) {

Why: The new "Dialog" implementation depends on the "Button" control now. Due to the above offending line, the dependency is not "optional" as stated in the documentation even if you don't use the new button control. If you don't include "button.js", you program will break at the above point.

Fix: If you are willing to change the source code, we can change the offending line to something like this:

if (YAHOO.widget.Button && oButton instanceof YAHOO.widget.Button) {

BUT, I am 80% sure, at another line, or in another control, I may run into the same problem again.
So, the best bet is to include "Button.js" to my web page.