Keyword freezes

When I keyword using the HUD sometimes it will freeze and just do nothing for a while or will do nothing for a while and the wheel starts to spin for an ungodly long time. Sometimes it crashes and has to be restarted.

It does this when I have selected several keywords and am about to drag them to a highlighted image or images. It just, dumbly, since there for a while or proceeds to crash.

Has anyone else experienced this?