Need some input on tweaking with new upgrade and router

[misery]

TCP properties for IP = xx.xxx.xxx.xxx ()
Browser/OS = Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050317 Firefox/1.0.2
Notes: Read the Analyzer FAQ if the above is not your IP address.
TCP options string = 020405b40103030001010402
MTU = 1500
MTU is fully optimized for broadband.
MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.
Default Receive Window (RWIN) = 64240
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 64240

RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
bandwidth * delay product (Note this is not a speed test):

Your RcvWindow limits you to: 2569.6 kbps (321.2 KBytes/s) @ 200ms
Your RcvWindow limits you to: 1027.84 kbps (128.48 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = ON
Time to live left = 51 hops

TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00000000 (0)

WINXP SP2
Comcast Cable: 6000/768 Upgrade
Set to FORCE 100 FULL DUPLEX
New Linksys ETHERFAST BEFSR41 4-Port VER. 4
no known firmware upgrades on linksys site.
CAT-5 Cable
AVG 7.0 PRO Virus, SPYBOT 1.3 TX, Microsoft Anti-Spyware