What you're seeing isn't a lack of antialiasing, it's a lack of subpixel antialiasing. Note the difference:


The colored edges line up with the "subpixels" on your LCD, so that a solid block of pixels is illuminated and it still looks like the right color.
The problem here is that Core Animation doesn't do subpixel antialiasing as automatically as it does when you don't use CA. The simple solution is to disable the CA Layer backing on your view (or whatever superview has it). Otherwise, this question has some more useful explanation and info about workarounds.