Pressing F7 or using tools->spellchecker brings up a blank spellcheck
window. If the document is correctly spelt, then the "x words checked"
box comes up, and the dialog remains blank. blank, or even not-filled-in
, i.e. the window manager draws a frame and inside it some old screen
contents still shows.
This works better if there are speling errors, the dialog then fills in
with the usual suggestions.