I can add an alias, hit save, then remove it.
It gets reported in recent changes as "(Added and removed [en] alias: The Golden State)"
The diff links to the addition of the alias, and the alias is still there.
http://www.wikidata.org/w/index.php?title=Q99&curid=230&diff=1698&oldid=497
http://www.wikidata.org/wiki/Q99
I don't see this issue in the latest master so it should be fixed when we can update the deployed branch to a newer version of the repo,
Version: master
Severity: normal