Warning: vsprintf() [function.vsprintf]: Too few arguments - When move mouse to the About Piwik button - on trunk

[anonymous-matomo-user]

When move the mouse to the button "Piwik 1.7.2 rc8", it show a lot of error instead of About Piwik.

My revision is 6224

The error message is:

There is an error. Please report the message and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: vsprintf() href='function.vsprintf'>function.vsprintf</a>: Argument number must be greater than zero in /home/chuongdu/public_html/tracking/core/Translate.php on line 213

Backtrace -->
#0 Piwik_ErrorHandler(...) called at [:]
#1 vsprintf(...) called at [/home/chuongdu/public_html/tracking/core/Translate.php:213]
#2 Piwik_Translate(...) called at [/home/chuongdu/public_html/tracking/core/SmartyPlugins/modifier.translate.php:41]
#3 smarty_modifier_translate(...) called at [/home/chuongdu/public_html/tracking/tmp/templates_c/%%FB^FB3^FB3A69AF%%header_message.tpl.php:39]
#4 include(...) called at [/home/chuongdu/public_html/tracking/libs/Smarty/Smarty.class.php:1869]
#5 Smarty->_smarty_include(...) called at [/home/chuongdu/public_html/tracking/tmp/templates_c/%%7C^7C6^7C60150B%%index.tpl.php:29]
#6 include(...) called at [/home/chuongdu/public_html/tracking/libs/Smarty/Smarty.class.php:1263]
#7 Smarty->fetch(...) called at [/home/chuongdu/public_html/tracking/core/View.php:133]
#8 Piwik_View->render(...) called at [/home/chuongdu/public_html/tracking/plugins/CoreHome/Controller.php:93]
#9 Piwik_CoreHome_Controller->index(...) called at [:]
#10 call_user_func_array(...) called at [/home/chuongdu/public_html/tracking/core/FrontController.php:138]
#11 Piwik_FrontController->dispatch(...) called at [/home/chuongdu/public_html/tracking/index.php:53]

[anonymous-matomo-user]

Attachment: The button which show error if I move the mouse over on it
piwi.png

[anonymous-matomo-user]

Attachment: My custom languages file
vi.php

[mattab]

please run the unit tests in trunk/plugins/LanguagesManager/tests/LanguagesManager.test.php
they will output a message with the problem