Major:
- server-initiated updates are still not entirely reliable: may cause
  memory leaks in browsers, and are sensitive to proxy servers closing
  inactive connections...

Minor:
- default display style (block/inline) for button is different in xhtml
  versus html? (see Dialogs example)
- key handling in SuggestionPopup.C behaves differently in different browsers
- getAttribute() in SuggestionPopup.C gets literal character entitites in Opera
- history tracking works properly only in Firefox and IE6/7
