IS blurring : does your 24-105mm f4 L have this problem?

Got a call from canon, and they said it's a normal behaviour. And it's normal that some lenses act differently than others because it's mostly hand made. THey say i'm using a too slow speed so it's normal. If i use a normal slow speed i won't see any difference. THey asked me if i could see a problem at 1/100, of course not, but i don't need IS at that speed.

So i tried at 1/30 and 1/50 at 105mm, and of course no problem.

I think i will never use IS on this lens because it's useless