Input Becomes Glitched After Trying to Convert Invalid Characters with NOMVNI Input

Binary package hint: ibus

* I'm using Ubuntu 9.10.
* "apt-cache policy ibus" says ibus 1.2.0.20090927-2ubuntu2 is installed.

Normally, when typing with NOMVNI (Vietnamese input), a valid sequence of Vietnamese quốc ngữ characters can be converted to Chinese-based chữ Nôm characters one at a time via a floating window containing a list of possible replacements. The window pops up when a valid sequence of characters has been entered and one of the number keys pressed. However, invalid character sequences may cause the text to follow the text input caret and the floating window for selecting Chinese characters will no longer appear although it will continue processing keyboard input as if it did.

The following is an example of such a scenario:
1. Activate IBus and enable the NOMVNI input method.
2. Press the following key sequence one at a time: [w], [1].
3. The text will follow the text input caret and the floating window for selecting Chinese characters will no longer appear although it will continue processing keyboard input as if it did. You cannot get rid of the "ghost" without switching to another input method.