<sigh>...I feel ya, man. I'm having a similar issue. Though I don't know the particulars, it seems that estates have a "default" grid that they load on, even if the actual placed furniture grid is not in line with this. It's a minuscule difference, so more often than not it doesn't change much, but sometimes....I've only seen it with partitions by the way. The only way to fix is probably on SE's end, and they have such a long "honey-do" list of "needs fixin'", it'll probably never be done...my only recommendation is over compensate and mesh the two partitions together, or just let it be...