That theory makes good sense, dont know if its true or not...
I have the same problems with my Dial-Up ISP from time to time. I either cant connect at all for ages, or it keeps cutting out, or i get a stupidly slow connection, i mean way less than 52k.
I was thinking of scrapping it and useing the 3G internet for when im away from My ADSL...
Oh, my ISP seems to have issues with Vista... They provide the update, but to get the update you have to be able to get online as it saves the update in temps and installs them, so no way to save the files and move them to Vista, or not that i have found.