SoW not working?

[gseiomfmfornesy]

I know this seems strange, but recently I've had a problem with SoW only increasing my movement speed in 'bursts'. When I have spirit of wolf up, I walk at normal speed, and only occasionally/randomly does the movement buff kick in for a moment. It seems to be better in some zones and worse in others.
I just installed bootcamp/titanium today on a 2010 macbook - I normally play on a desktop and have not encountered this problem.

Has anyone else had a problem with SoW not working, even when it's been freshly cast and shows up on the buff window?