I have been trying to insert an uploaded picture into a post since I (locally) installed 2.5 RC1. (Now upgraded to 2.5)
I have no problems uploading my pictures, but then it seems to go wrong.
I hit the add Media -> add a picture-button, then I choose the 'Media library' where I choose the picture I want.
Title, caption and description are already entered, I chose to have no link, choose the alignment and size I want, hit 'insert to post', and then the middle of the 'greybox' turns white, and nothing else happen. When I close the graybox, by hitting on 'x', (which is the only thing I can do), nothing has changed to my post...
Maybe (as a non-english-speaking user) there is something I misunderstood, but when that's so, it should be made a little bit easier.