I hope to change this review when I am finally contacted back by support@nullriver, but to this moment none of my three emails sent over the last 10 days have been responded to. so I am forced to write a bad review. I downloaded Medialink to my 1st Gen Intel iMac 10 days ago. It installed with no problems. Once installed I paid for the activation code and registered the product. I did this before I fully tested out the software. This was my mistake. Once registered I went in to the other room to check the ps3 and found the system was reporting a DLNA Protocol Error 7531. But there is no information on their website regarding this issue. With this error by ps3 does not recognize any files on my computer at all, no music no movies no pictures no file structure. I have emailed Nullriver 3 times and never heard anything back from them. not even a "we got your email but cannot respond at this time, please be patient". Help! I would like to use this software and not have to go back to Nullriver and demand my monies back. Help, Help!