Sharpness drops whenever I turn IS on

Hi everyone. Im new here.

Always read Brian`s reviews, but actually never saw that "community" button up there at the main page!

Anyway, I have a question for you guys.
The only lens I have which has IS, the 70-200mkII, shows a strange behavior whenever IS is turned on: it takes slightly soft pictures. Sometimes, they would probably be softer without the stabilization (when using shutter speeds well bellow 1/200, at 200mm for an example) but when I`m around 1/200 or a little faster, I get much sharper shots with IS turned off. I rarely get a super sharp shot (around one in ten) with IS on, unless I`m using really high shutter speeds or using flash, which freezes motion. In those situations it is always ultra super sharp.

Could this be a faulty IS unit in my lens? Has anyone seen this before?

Welcome Vik

At a point your shutter speed is fast enough that IS will not matter. That wouldn't be at 1/200 at 200mm.
But no, I have never noticed this with my copy and I never turn the IS off even when I can get the faster shutter speed. I have heard arguments that you should when you get in to faster shutter speeds, but I tend to be overly picky on such things and I have never noticed a problem.
If I did notice this I would send it in to Canon to check out.

I wish I could remember the whether the IS drags along even when not "engaged". A quick email to Canon should tell ya. Mine had the same problem and thought it was just me or the 40d. Once I sent everything in to canon, they found the IS dragging down the focus and fixed it. The lens was awesome after that.