Scroll cursor/bar cannot move after using writer for a while

LibreOffice Writer version with Zotero Plugin. On MAC 10.8.3.

After use the writer for a while, I found I cannot move the right size scroll bar/cursor up and down to navigate the pages any more. Save the file and reopen the file solve the problem. but I don’t know that triggers that. Might be a Bug ?

Take a look if this bug fdo#53351 looks something like yours or if you can find any other which would. If not, please file a new bug report.