Yes connected firmly. If you do a google search the problem you are having is similar to complaints by others that used non shielded cheap no ferrite core cables. . Data integrity is important especially for the p2 workflow. why take the chance with cheaper cables. I'm not saying its the cause of your problems but it could be. granite digital has great cables with triple shielding ferrite core gold plated connectors designed for data integrity. They are also really flexible so as not to put a strain on the cable and port like stiffer firewire cables I've seen.