Ubuntu Networking :: No Speed Improvement With Gigabit NIC / Switch?

I recently upgraded a server's networking card to a Gigabit NIC, and got a hold of a Gigabit switch (Here's a link) in the hopes of increasing my network performance - however, I'm getting around 10 MB/s throughput now, which is exactly what I used to get with the old 10/100 switch & NIC. The new switch recognizes both computers as Gigabit (the other machine has always had a Gigabit NIC), and both computers say they're gigabit - I've found various sites around the interwebz recommending tweaking some TCP/IP buffer settings, which I have tried to no avail. I also saw that hard drive speed is usually the limiting factor. According to "hdmarp -t", the server HDD (definitely the slower of the two) is:

Code:
Timing buffered disk reads: 226 MB in 3.00 seconds = 75.26 MB/sec

So that's obviously not my issue. The cabling is CAT6 - I ran it myself, but if I'd mis-wired the end connections, wouldn't it just not work at all? I admit, I bought cheap NIC's (I'm not going for like 124.9 MB/s throughput here..), and I didn't expect them to be stellar, but I certainly expected the speeds to improve. I'm moving files from a server running Ubuntu 9.04 to a Windows machine - I've tried both my Samba shares on the server and an SFTP transfer: they both have about the same throughput.