Wow. I don't usually have the import options checked but I did last week while importing a mulitpage pdf file.
It must have defaulted to unchecking that box for some reason.
At your suggestion I activated the options, checked the transparency box, imported a graphic nice and transparent.
Then to test I unchecked the options box on the next import and it remembered the checked transparency box.
You just saved me from the dread of replacing my preference files.
Thank you so much.