Cannot use download website because of IP address

I cannot download from websites such as Rapidshare and megaupload, its says my IP address is already downloading a file or has exceeded downloads even though I haven't been doin neither. I'm wondering if my address has been hijacked, please let me know what I could do. Thank you very much I appreciate this

 

It could be that it is a range of IP addresses that is being recognised, rather than just yours. I've had the same thing happen a few times with sites for looking up post codes, even if it was the first and only search I had attempted to make on a particular day. And twice, I got accidentally banned from Lockergnomes forum when the guy who looks after the forum software banned a certain range of IP addresses due to spam. (and no it wasn't me, I'm a moderator on there)
Depending on your internet service provider, you may have a floating IP address. If you have, and you reboot the computer, you may have more luck. Other than that, I don't know.

 

This started about a week ago so just rebooting my computer doesn't work, is there any way to change my IP address? Thanks