I've seen it on my system and is replicable in demo.otrs.org if you split a ticket, then select the queue that ticket will be inserted into, then a script error occour. On the lower part of the page displayed, some ticket are displayed without any link between each other. In 1.2 that ticket where almost coming from the same customer Id. On my system I've deleted all the ticket (where only 2) now the error is not displayed anymore but when I select the queue where the new splitted ticket will be put into no tickets are displayed below. Ciao AleX