I have said it before and I will say it again. I love the my files block . Superb addition and the kids use it all of the time to swap files back and forth.
Just had a student try to upload a file to the shared_files block in our moodle install and he couldn't get it to work. I logged on as him and it worked fine for me. He eventually realised if he turned his firewall off it worked.
Any reason for this? What was the firewall blocking? He wasn't very forthcoming with the error message but it did seem to refer to the my files add.php page
Not a huge issue - just interested in case it comes up again.