Generally, I keep my Dropbox files off-line. In the past, if I marked a particular file "make available offline", the circle next to the file name would turn green fairly quickly, and the file would then be available on my driv drive immideately. Now, however, the "make available offline option seems to have no effect. If I try to access a file, the access is veery slow and sometimes fail completely. However, I can usually still access files if I wait long enough. Also, I can move files (very slowly) to a flash drive. why has this change occurred?