Thanks everyone!! I think I've figured this out, let me recap to make sure -
PS4 always saves in the .psd mode - so for posting save a "copy" in the jpeg mode to load to Photobucket, etc. Also, this extension doesn't happen until you edit a photo, is that correct? So unless I edit something I've downloaded from my card, they are stored in jpeg?
I've never had this happen before - like with daisy pictures I posted on the macro thread - they saved to jpeg without me selecting it - that's why this threw me!
My normal flow for editing is - open the photo in edit mode - make a copy - make all changes to the copy - then I "flatten image" and "save as" . A title box pops up with the name and suffix that says, "edited" behind it. This is the first time I've had the ".psd" pop up there as well. And I wouldn't have noticed except that Photobucket wouldn't load my image!? Will photobucket take .psd images or just jpeg? Thanks again and I'm sorry for all the questions - need to find that instruction book for PS4!!!