on xxx.13 (the f/w I started with) has some stuttering when playing iso over network, but was hardly enough to even mention. xxx.16 f/w was horrible.
but the symptoms were not conclusive enough to rule out the server (in this case was either a server 2008 or win7 ult machine) , network, or hub itself.
so been messing around last few days and it seems the real culprit is the netgear GS608 switch.
config is windows SBS 2011 domain controller with prosafe GS116 switches at trunk then cascaded to GS608 in area the hub is at. Media is presently all on WIn 7 ULT machine.
swapped the GS608 out with a netgear prosafe FS116 and so far no stuttering at all.
thought I would mention it in case someone has odd stuttering they cannot rule out, may be worth swapping spare switch in place to test.
edit: corrected switch model to GS608
