all cards are set to full duplex (no auto negociate here)
no idea what NIC comes in the xbox, and yea, it seems the xbox 's ftpd is pritty fast (in XBMC) however transfering to the xbox // and back is still the fastest thing i can do on my LAN
Exepet tryin to swap the "noname" NIC im really clueless!
The Xbox part is especially weird!
Does each device have a different brand of network card? I sometimes get very low speeds between different brands of network cards. I know it shouldn't matter but I've seen it. My moms computer would get about 2mb/s to my file server while every other machine in my house got almost 11mb/s (on a cisco 2900xl switch). Her computer had a netgear card instead of 3com which all the other computer had. I swapped a 3com in and she was up to almost 11mb/s.
Had a similar problem to this and it turned out to be 4 x 470MFD electolytic capacitors in the power supply filter section of the Linksys switch. The capacitors had "vented" and were no longer doing their job.
Once I'd replaced them the data transfers via the switch were comparitable with transfers that didn't use the switch.