Getting Trasparent Images from Photoshop into Illustrator (*CS6 edit)

I find hits for this on Google issue going back nearly a decade, so while it's no isolated incident, no solutions I've found that have worked for me.

Simply, I am trying to bring an image made in Photoshop into Illustrator for the purposes of creating a vector image for a t-shirt design.

The image has only one layer and contains transparencies. I have tried saving it as png, pdf, psd, eps. I have tried several methods to bring it in; simply open it normally, copy/paste, "place", drag/drop... all with each type of file mentioned. Nothing has worked. Every method yields the same result - a white background with all transparency lost.

Note* Yes, the transparent grid is visible, the image is definitely not transparent after it is brought into Illustrator. It is solid white. I mention that since it seems a very common first reply to this question elsewhere.

I can get my transparency back by tracing with the 'ignore white' option selected, but unfortunately that's not an viable solution as there is white in the image itself that needs to be retained.

I've run out of resources after scouring forums, youtube, etc. with no results. Any suggestions would be greatly appreciated! Thanks