Samba server slow - laggy video in high bit rate scenes

[jw1001]

Is this Windows XP? If so, you could be seeing underlying latency issues that are a limitation of the SMB (CIFS) protocol. There's a basic explanation in the Wikipedia article on SMB. Version 2 was introduced in Vista partly to address this issue.

Using DLNA - a streaming service - you wouldn't notice this problem, but SMB is (as name indicates) a block protocol which needs frequent acknowledgements and the higher wireless latency will affect it. You could research to see if there's a way to tune TCP or SMB settings to improve throughput. Or use this as an excuse to upgrade Windows!