Upload speed when streaming issue

Hello all,

I just purchased NAS Synology DS 412+ for streaming in my LAN. When I tested the D/L and Up load speed from my nas, it worked just fine with 100+mb/s

However, when I ran XMBC and tried to stream Blu-ray movie with DTS-HD, the upload speed seem to be only 3-4mb /sec, which impossible to run it.

I tried all method of connection:
SMB
UPNP
MAP DRIVE:
all same issue

Any ideas?

My PC Detail:
Window 7
I7 550TI
XMBC FRODO 12.0
Gigabyte Lan with Cat 6 cable.

NAS:
Synology DS 412+

Thanks for all of reply in adance