Illustrator :: Resampling 300 Dpi Images To 72 Dpi Upon Importing?

A few weeks back my illustrator started resampling all of my high-res images to 72 dpi upon opening.
 
example:
 
Image A: Resolution 300, 877 x 591
 
I'll open that image in Illustrator (which, I've been doing for 8 years without problem) and here is what happens --
 
I get a bounding box of 877 x 591 - HOWEVER, the image is floating within that box at (what I'm guessing is around a 72 resolution) 213 x 142 pixels.
 
If I save the file out at 72 dpi - the image pulls up the right size in illustrator - it's just any image file that's a higher res than 72.

I'm running CS5