Impact handwraps broken, or am I confused?

Quick Q about the effect of Impact handwraps...

I've been building up these:
http://mitnal.com/ddo/Impact-handwraps.jpg

Did a force ritual and added an icy burst kit, so there's been a fair amount of time/money invested in these things (and they're BtC anyway, so I can't even fob them off on some poor sucker :)). My understanding of Impact is that it's supposed to double the critical range, so for handwraps, it should be 19-20, no? I'm not seeing that on the description (see pic); somebody mentioned it won't show up there, but I'm *also* not seeing it from the combat log. A 19 just rolls normally, every time, while a 20 counts as a critical hit.

Just to test, I bought another pair of Impact handwraps from the store, and they have the same non-functionality, so I'm wondering if I'm just completely confused about what's supposed to happen, or if they're buggy. Nothing I've tried seems to matter, e.g. stance, pajamas and so on.

Dang it.
Just about finished dinging 25 on my monk and have a pair of +1 impact of lacerating , icy bursted waiting for TR(and finished farming tokens)
Glad I didn't force ritual them yet.

Was thinking of waiting for the EnH pass before TRing anyway don't know if I could get a pally past life in before it released.