Hi Klas,
Looking for, I read that could be due to a bug in Joomla!. In older versions (around 3.3 or early 3.4). Sometimes Joomla! would create a new #__extensions table record for the updated version of a component (ANY component) it was installing, therefore creating a duplicate update record as well. Further to that, for reasons unknown Joomla! would sometimes create a new update site record when updating an extension if the URL was different.
So, on my Joomla 3.4.8, with phpMyAdmin I deleted the "Div Field Plug-in Updates - http://update.seblod.com/plg_cck_field_div.xml - CCK Field - Div - Site - Plugin" row in the two tables:
- #__update_sites
- #__update_sites_extensions
Then, I reinstalled Seblod 3.7.2.
The "Div Field Plug-in Updates" do not appears anymore in "Joomla - Extensions - Update Sites".
So, from Joomla 3.4.8 and Seblod 3.7.2 the problem seem to don't be present anymore...
Many Thanks for support