In the serials-edit.tmpl subscriptionid is defined in every row (issue) of the serials edition table. If you click on the save button, multiple subscriptionids are passed to the serials-collection page (serials-collection.pl?subscriptionid=3&subscriptionid=3&subscriptionid=3&subscriptionid=3). This results in duplicate lines in the serials-collection page for each id that is passed.
Created attachment 2156 [details] [review] Proposed patch
Please ignore this patch. It looks like serials-edit can edit more than one subscriptionid at a time, although I'm not sure how you would do this within contriving it. The fix needs to be able to send multiple different subscription ids, or serials-collection needs to perform a DISTINCT function to eliminate duplicates. Not passing duplicate ids in the first place would probably be preferable.
Created attachment 2160 [details] [review] Propose patch - replacement for previous patch
Pushed second patch. Please test and close.