I got same behave on Ubuntu 8.10 (with all software, kernel updated till 2009-04-17)
1. Select a word, press shortcut to show floating window
2. Move mouse outside to close floating window, still keep selected word
3. Press shortcut again, no floating window appear
4. Even I re-select the same word, still no floating window appear.
I have to select another word first, scan by press shortcut key, then select back the desired word.
I got same behave on Ubuntu 8.10 (with all software, kernel updated till 2009-04-17)
1. Select a word, press shortcut to show floating window
2. Move mouse outside to close floating window, still keep selected word
3. Press shortcut again, no floating window appear
4. Even I re-select the same word, still no floating window appear.
I have to select another word first, scan by press shortcut key, then select back the desired word.