The single HISAT job is likely in the queue, but we will check you account (found it) to make sure more is not going on. Should there be an issue with job dispatching, we will post back again.
It is generally best to allow queued job to execute to completion, but in some cases, re-running the job with the target cluster set to Jetstream can help. How-to on the tool form: http://imgur.com/a/LvLXL
More about dataset status: https://wiki.galaxyproject.org/Support#Dataset_status_and_how_jobs_execute
Thanks for reporting the issue, Jen, Galaxy team