I've always had the opposite on mine ever since the start.
It's a light steed and I find that tapping the key once will cause my War-steed to walk a couple of steps and then stop, I have to tap it 2-3 times or hold it down for a moment to just get it to walk.
[center][url=http://forums.lotro.com/showthread.php?18699-How-to-get-help-on-the-Tech-Forums-and-how-to-contact-Turbine][color=gold]How to get help on the Tech Forums and how to contact Turbine[/color][/url]
[color=green]Please reply to the topic or PM me if a solution I posted works for you: The more data I can gather the better I can help.[/color][/center]