Steve
I dont know if you notice this.. 
This is what I observe:
I upload a new file
Select the File from my site
Select the Image from my site
Then when I select the category,

The file and image in the drop down above is reset or points back to the first item in the list.

So as a work around I ALWAYS select first the category and THEN select the Image and the File.
I think its because the page is refreshed each time I select a category.

I  dont think this is a major issue but for those may not be aware they have to check again the File and Image before pressing Upload button
thanks
Ariel