I have had this issue a few times.  Tonight I am doing 10 Expenses and 5 JEs.  Attached to all 15 transactions are the same 2 pdfs.  I attached them all, then went back to enter the data -- had not hit save yet, giving them time to upload - and no they are not huge files.  First 5 expenses with the attachments -- got to 100% but said they were still uploading.  Next 10 uploaded just fine.  That is crazy.  If anything you would have thought the last 5 would be the ones with the hiccup.  But no.  Plus I gave it 30 minutes, still did not upload and let me save.  I then detached the attachments -- STILL won't let me save the transaction, and cannot refresh.  I am going to have to start these stinkin 5 expenses all over again.  The exact SAME attachments, same browser -- GO FIGURE