I wanted to add a couple more details to the omnipresent ref set issue, because I just got a couple more omni-sets (beginning on v1319_s1_p078.jpg). It seems that when there are multiple reference sets on one page, an extra ref set appears that was not created by the user, and this set is un-deletable. As well, when one of these ref-sets that I appears, one or more reference sets that come after it become omnipresent as well. In both of the last two occurrences, there have been multiple reference sets on one page, and some of these reference sets include the same date, but different collecting events, because they occur at different localities.
I don't know if that helps...
Jessica