flash cookies? I had choc chip earlier... Clearing cookies, temp files, and everything is good enough. If you are still blocked, then yes it is your IP. Restarting your router makes no difference. Some people can reboot their internet modem and get a new IP. Others are on a lease and that doesn't work. You have to change your mac address on your router in order for your ISP to issue you a new IP.
Heres what I did to get a new ipaddress after it was banned from youtube even thought I am on cable modem. I just formatted my harddrive and restarted everything and I got anew IP addy with my formatted hard drive. I thought it was kinda wiered but hey it worked. Thats just a long route of doing things. Do you know why they are banning your ip addy?