Please help me if you can with my glitchy connection...mostly playing on-line games. In games, I'll get the little icon that pops-up telling me the connection is laggy and game play can be vomit inducing. Offline stuff is fine. General web surfing is acceptable, but not great.

My connection should be much better, but I get tons of lag. I don't understand!

My Connection info:
Fayetteville, AR, USA
Cox Communications
7Mb/s down, 512kb/s up!!!!

My computer:
Newish Shuttle SN27P computer AM2 2.4 X2 processor, 2 gigs 4-4-4-4-12 mem, 260 Gb SATA2 HD, fairly uncluttered OEM version of XP pro with all aplicable updates, including SP3 release candidate, GeForce 8600 GTX graphics card.

Also, If I check my connection on SpeedTest.net, I get rediculously high download speeds - usually 18-22Mbps (Not a typo - 22,000Kb/s!!!) and upload is usually 500+kb/s.

Here is my report:
SpeedGuide.net TCP Analyzer Results
Tested on: 01.12.2008 02:23
IP address: 72.204.xx.xx

TCP options string: 020405b4010303000101080a000000000000000001010402
MSS: 1460
MTU: 1500
TCP Window: 64240 (multiple of MSS)
RWIN Scaling: 0
Unscaled RWIN : 64240
Reccomended RWINs: 64240, 128480, 256960, 513920
BDP limit (200ms): 2570kbps (321KBytes/s)
BDP limit (500ms): 1028kbps (128KBytes/s)
MTU Discovery: ON
TTL: 55
Timestamps: ON
SACKs: ON
IP ToS: 00000000 (0)

I have played around with this trying different recommended RWIN values and moving around that connection speed slider on the TCP optimizer program. I honestly don't notice a difference. Speedtest.net results don't change much.

Why is my connection not flying? Lag? Latency issues? Also, my last computer: Shuttle SN95G5 V3 only had 1 gig of slow ram, a single core 939 3200+ processor, and a modest videocard. Overall it was slower, but it did not experience the internet lag. Should I try the next connection speed 12Mb/s down and 1 Mb/s up? Only costs $15 more per month. I know Shuttles SN27P has gotten some bad reviews on newegg.com for compatability issues. I don't have a spare slot to try an add-on network card because of the GPU heatsink I could try connecting to cable modem by USB?

My computer knowledge level is moderate in general - I build my own computers, but i am far from a programmer. Help me if you can!!!

Seriously, thanks for any input.