Not sure if this pertains to your issue but if you are connecting via WIFI check your router settings and try turning on protect mode.
My router is a Belkin and protect mode resolves issues with 802.11b traffic.
My windows laptop (client) is 802.11n and my MacMini (server) is 8.2.11b.
As soon as I enabled this setting my issues was resolved.
Hope this helps
GSW