I'm having a recurring problem with LibreOffice in which I have a number of files open, but can't access them. Normally if I click on the LibreOffice icon to the left of the screen, I see small versions of all the files I have open. But when this problem crops up (which has been happening fairly frequently), clicking on the icon just opens a new file. Also, when this happens the little triangles that show up next to the icon disappear. However, if I then start closing files, the previously opened ones will appear, apparently in the order in which I had first opened them.

It's not clear to me whether this is a LibreOffice problem, or a Unity/Ubuntu 12.04 problem. It may be that the problem lies with multiple instances of a program being opened in Unity.

The only way I've found so far to stop this problem is to shut down the computer and restart it.

Has anyone else encountered a problem like this? Any ideas on how to prevent it from happening, or--if it does occur--to get it working again without restarting the computer?

I'm using LibreOffice Build ID: 350m1(Build:2)