Hmmm, I'll try getting rid of Registry Mechanic then.. By rebooting, if you mean trying to refreash the IP address, then I have done that.. And I've turned it off, pulled the power plug out, pulled all cables out and re done it all.. That didn't change much or nothing!
I still do browse while I'm downloading.. I was downloading the SP1 for Vista the other night.. Some 450mb and the speed of the download stayed at around 130kbps the entire time which is rather good for me! And I was browsing at the same time..
I haven't tried calling optus yet as they won't talk to me (it's not in my name..) But it could be my modem dying.. I have a Linksys and I hate it! haha, so if it doesn't all fix I guess I'll have to try and buy a new one..
And yes, I regularly clear out the cookies and temps..