1.7a_sp1 problem w/ HDX buffer

Had to have my Unitiserv 1TB drive replaced with 2TB.  When returned found it necessary to upgrade firmware on original HDX 400GB to 1.7a_SP1 from 1.6b...3 step process.  When finished, I now find it impossible to listen to my Seagate 2TB Go Flex Free Agent Easyshare drive that backed up my old Unitiserv drive (previously no problem with 1.6b), buffer kicks in every 10-12 seconds.  Have tried to work with reboots and share settings on latest version of Desktop Client but no joy.  Am using Netgear WNDR3400V2 router, using USB 2.0 because of Seagate drive.  Any ideas, please.