Host <--> Arduino wiznet ether shield and WireShark

hello,

on my project with a mega2560 and an ethernet shield wiznet microsd, i'm experiencing , most of the time, delays at the server connexion through my explorer.
i'm using TinyWerServer, which i'm pretty sure is not responsible of that delays.
I've slightly hacked the Tiny library to send 1400 octets sized packets instead of 160.
When i send a request to the arduino for a simple htm page less than 1Ko sized, it then starts the connexion but, it takes about 5 to 10 seconds to respond, then the result is usually quickly displayed.
1/ my firewall log stated that it'd blocked several connexion from my arduino despite a special rule allowing connexion with arduino (on the same subnet) .
2/ wireshark shows a bunch of packet between my host and arduino, exactly 3910 packets total size 232Ko
3/ most of the packet, 99.8% are 40 to 80 octets sized and are [TCP window update], [continuation or non http traffic], [TCP DUP ACK], [TCP RST], [TCP Retranssmission] wwhich seems to me that there are errors or problem on the connexion
4/ only one packet contains my html page
5/ Doing connexion to, for example, my printer web server, shows only regular packets with no errors and no delay.

it seems that ethernet library as some problem on my config. does anybody else experienced such delays, and took a look on packets with wireshark ?

just for info, i'm using ubuntu desktop 10.04

forex2:
I've slightly hacked the Tiny library to send 1400 octets sized packets instead of 160.

Why did you do this? What happens if you un-hack it?

I have commented on this with regard to data collection packets.
Keep your UDP packets short sweet and to the point.

UDP does not track lost packets.

I'm short of time so if you want to see what I said about margining out the UDP and data collection systems I'm doing track down my recent posts.

In short -- your experience is hardly unusual.

@gardner:

Why did you do this?  What happens if you un-hack it?

my aim was to speed up my connexion but it seems that it was not the best way
if i unhack, i have the same result regarding wireshark packet capture. same bunch of tcp protocol error messages.
except the firewall logged messages which have disappeared, everything is the same ...
i have to try with another ethernet library. for now i dont have much time

@WillR: i'm not sure to understand your post because, all of the problems seems to be tied to tcp protocol