Reported by mdcurran on 2014-04-01 05:59
When typing in Vietnamese in Windows, people may use the Unikey typing software, as it is possible that Windows itself does not support Vietnamese input. However, as of NVDA 2012.1 and the support for handling injected keys, it has become impossible to use Unikey and NVDA togethr as when correct key sequences are typed, incorrect characters are spoken and written to the control with focus. This is because Unikey will sometimes quickly backspace one or more characters and regenerate new ones, but as newer NVDA versions initially block the backspace key and then handle it asynchronously (which does include sending it on to the application) this is enough to greatly confuse Unikey.
Unikey can be found at: http://www.sourceforge.net/project/unikey
Notes from a user on how to reproduce the issue:

• choose english interface so that you know how to go along with it.
• select unicode (radio button) at settings character set:
• select telext (item) at input method combo box:
• type in ms-word the following string from keyboard: hoangf moocj kieen
    expected words being created in text: u'ho\xe0ng m\u1ed9c ki\xean'