I replaced the offending computer with another machine. The replacement had no trouble with shaw, but I was still suspicious, so I ran it all day yesterday doing a download and there was no problem. This morning I turned it on, ( it runs Ubuntu 7.10 ) and still had no trouble with shaw internet. So I suspect something is wrong on the original computer. Maybe the nic is going, or the hard drive or perhaps a virus? I didn't think Linux got viruses. Anyway, I'm going to be busy hunting down what might be wrong with the offending computer. This could take some time. I'm sort of disappointed that I can't blame shaw for this problem.