I wrote a program that sends stats to a server via http. It can send a lot of packets, like 20 as fast as it can... and after some time i cant access the site anymore. I can ping it and do a traceroute but cant access it via http.
I talked to my isp and they weren't very smart but they said it wasnt them, and the hosting company said it wasnt them... so what could it be?

Could be to much information and the servers cant cope or the site is takeing action as if it is a virus and is blocking.
Goodluck

uhh erase the cookies if there are.. then spoof yo ip add.. don;t know if it works.. but I always spoof my ip if I got blocked from blah blah blah.. then I can access it again..

Windows XP SP2 imposed a TCP connection limit. Check your windows event log: Start -- Run -- eventvwr.msc -- to see if this is your problem.

You can increase or remove the limit:
http://www.speedguide.net/read_articles.php?id=1497

If this is not your problem then something is likely throttling your TCP SYN packets (new connections). After you send the stats with your program then open up a command line and "telnet www.site.com 80" and see if the telnet session opens up. If the session opens type "GET /" without the quotes and press enter a few times. Note what the server does and how long it takes to respond and post it back here.

in my code i didnt close the connection right, so after it quit the server kept sending rst packets