It appears that the Layout is doing some funky duplication stuff and that an extra section has been added which shouldn't be there.
1) When labeling a module position in the backend layout it duplicates on both the highlighted sections (attached) which is causing duplicate modules to be posted when published ...
you can remove one of them. goto joomla backend > extensions > templates manager > socialize
under layout tab > click "save as copy" for default and clone it as default-copy
after that this new file will be created:
/templates/socialize/local/tpls/default-copy.php
I saw it at backend. you not make any copy for default layout yet. please check it. I just made copy/clone default template.
because I dont have FTP access detail. please edit that file (see prev post)
after that you can see from layout setting. there is will no have duplication position any more