I'm using LibreOffice Version: 4.4.5.2 mainly for Calc. I noticed that dialog windows often weren't receiving focus until I clicked on them. I tried fiddling with my Openbox setting to force focus for such windows but that didn't help. I also turned off Compton in case that was the culprit. Now, I googled the issue and came across this: http://askubuntu.com/questions/58077...-find-dialogue.

The answer there works for me.

Posted just in case the issue's been bugging others.