Safari hanging up due to Dropbox contextual menu plugin

最近、気がついたら、 Safari の Contextual Menu を開こうとするとしばらくハングするようになったので犯人探しをしてみました。
Dropbox にバグ報告をしようと思って英語で書いたものです。

Recently I got Safari hanging up when I try to pop up contextual menu in Safari.
So I sampled with Activity monitor.app when Safari got hang.

...
  1724 TContextualMenuPlugin::LoadCMPluginsFromCFPlugin(FSRef const&, __CFArray*)
    1724 DropboxPluginFactory
      1724 AllocDropboxPluginType
        1724 reconnect
          1724 connect$NOCANCEL$UNIX2003
            1724 connect$NOCANCEL$UNIX2003

I found a suspect.

~/Library/Contextual Menu Items/DropboxPlugin.plugin

After removing DropboxPlugin.plugin, Safari's contextual menu is popped up as smoothly as ever.
However, every time Dropbox.app is started, it places the plugin. As I'm a programmer I can't bear torment of removing the plugin every boot time of Mac by hand. So I renamed the plugin:

$ mv /Applications/Dropbox.app/Contents/Resources/DropboxPlugin.plugin \
/Applications/Dropbox.app/Contents/Resources/DropboxPlugin.disabled.plugin

I'v used Dropbox for most half a year. Until this problem happened, it works great. I couldn't remind when I upgraded Dropbox app recently, so I suppose other changes of mac caused this problem.

Mac OS X 10.5.7
Safari 3.2.3 (5525.28.3)
Dropbox.app 0.6.402 or 0.6.507