Yes, I have experienced a similar problem when uploading. I just ftp my images directly to the server to overcome this problem.
I also have permission troubles with JB-Latest (JoomlaBoard Forum latest module). If you are not logged in it won't follow the link to the boards. Error: You are not authorised.
This will be fixed in the next version of jAwards, there is already a bug tracker for it. Until then, please upload your medals manually into images/medals.
In one of the last Joomla version, access to the media manager was restricted (Security reasons?). If someone knows how to use it nevertheless, please let me know.