Ok, just after I posted this, i took another look at the folder, and noticed another .htaccess file in the 'assets' folder
In here, it gives a list of permissible files - so I just had to add JPG into the list.
Allow from all
JPG files are pretty common, so hopefully this fix can help others!
Bless you Jon,
you just saved the day over here.
This really should be rolled in, or handled differently altogether. Maybe automatically lowercasing file extensions extension on upload?
Most of the clients i work for haven't even seen a file extension in their lives.
Thanks a bunch again,