Issue 117012

Steps to reproduce
1.	Create a new presentation
2.	Type some misspelled text on the slide
=> the wrong word is underlined 
3.	Click somewhere outside the text block
=> typed text has appeared on the slide thumbnail in the “Slides” pane
4.	Right click on the misspelled word and choose “Ignore All” in context menu

Actual result: All text in that text block has disappeared on the slide
thumbnail in the “Slides” pane. The text cannot be restored by right/left
clicking on the slide/thumbnail.

Notes:
1.	The text on thumbnail could we restored by applying some changes to the slide
(editing text, changing layout etc.) or adding a new slide to the presentation.
Looks like thumbnails are redrawn at the point.
2.	If there are several text blocks on the slide only the one with misspelled
word disappears.
3.	The same issue occurs when you add the misspelled word to dictionary except
of ignoring it (context menu --> Add -->[name of your dictionary])
4.	The same issue in OOo3.3 except that missing text can be additionally
restored by right-clicking on the “Slides” pane