elFinder

Hello.
I'm using elFinder with CKeditor on my website (based on Zend Framework). When I right click in elFinder area context menu apear normally (reload, new folder etc), when I have 2 or more files selected it's also ok (copy, cut etc..), but when I right click on file, nothing happens, and firebug trows an error:

this.fm.params.extract is null
[Break on this error] return this.fm.cwd.write && this.fm....mime, this.fm.params.extract) != -1;
elfinder.full.js (wiersz 2228)

is there any solution for this?

Best regards, and thanks for this great file manager!