Windows 7 - Libre Office & Open Office file associations

I realize that this is not primarily a Windows7 problem, but it just bothered me to see one program stopping me from setting the file associations for another program. And I need to vent.

I have been running both Libre Office (LO) and Open Office (OO) for months now, not a heavy user, just trying to keep both going while I figure which one I liked best. These apps share file extensions, and are very file compatible, and I had always been able to open the same document in either

Both families of programs pinned to the Start Menu had, for months, contained file history of many documents, some documents showing as history in both app-families, and able to be opened in either LO or OO. Yesterday, I upgraded Open Office. First thing I noticed, the LO apps pinned to the start menu had their document history icons changed to OO icons. Sure enough, these documents, in the history list of a pinned LO app, open in OO. Rats, I think--I guess I will have to re-assign the extensions to LO. . . . No can do! I have never had this happen before, but I now when I use "Open With" on a file with the shared extensions, (.ods, .odt,...) then "Choose Default Programs...", then "browse" to set a new default, the LO app does not stick. So far, I am unable to set the file association to any of the LO apps.

I have occasionally seen software, usually pretty sleazy and undesirable software, that would hijack file associations, would take-over as much of the computer as possible. But at worst, they just made it inconvenient so that the user would have to go back and re-assign the desired apps. But I did not expect to see a professionally done app like Open Office to do this sort of thing without asking. And for sure, I did not expect to have an application block my ability to re-assign file extensions to to another app

Does this sound like something wrong with my system, or does it sound like the way OO should work, or do I just sound crazy?

I think the problem here is that Libre Office is a recent fork from Open Office. At one time they were so close that you couldn't have both loaded on the same system.

They worked well together for months, and as near as I can see they are completely separate app families. A more likely explanation, seems to me, is that the teams are fighting, and using methods that I cannot fully describe in polite company.

edit: plus a brief experimentation suggests that they both work fine, it is just the file associations are broken in a way that I have never seen before.