G11 - control wheel question

I'm just getting started figuring out how to use my new (to me) Canon g11, but I think it may have a problem...

When the g11 is in Av or Tv mode the shutter speed or aperture scale image isn't always on the screen, I can turn the control wheel and the scal will only appear every few seconds, and when it does it's not very responsive. For example in Tv mode the "1/125" is there along the bottom, but I can turn the control wheel for a few revolutuions without anything changing, and the the scale will appear above the "1/25" and it may or may not increase or decrease as I turn the wheel.

Something's wrong - right? Shouldn't it be there as long as I leave it in either Tv or Av mode, and shouldn't it react as soon as I turn the control dial?

Thanks.