Quote Originally Posted by Daniel Browning
If noise is the issue it could be related to the fact that noise is more noticable in areas that lack detail (such as defocused spots).

I think this is the issue, at least with the basket shot. The area at the bottom of the basket is outside of the depth of field, so there is no sharp detail to distract you from seeing the noise (but it's there, even ISO 100 has some noise, especially on an APS-C camera like the T1i you're using).