Ward of Stability Glitched?

I'm developing a new build to farm due to the recent update (im loving this challenge btw) and i was doing some testing with ward of stability. I dunno if its just me or is it not working? I still get knocked down even though I have it active on me. Anyone else having this problem?

I'm having an issue with the Vermin that I can't pinpoint that might be related to your problem. It seems like I am getting interrupted by Jagged Strike with Ward of Stability up even though Jagged Strike shouldn't interrupt (or even knock down for that matter). However, I'm still safe from Entangling Asp, which does knock down. None of these skills were updated; so, I'm inclined to believe it's some sort of bug.

Hmmm. Yes I think this must be a bug....hope anet sees this and fixs it soon. My ranger wants to farm vermin again...