Considering what you describe, and the hijacking of DNS services in Europe by the RPC a while back, I wonder if they could be rerouting some subset of internet traffic through their servers along with the recent change to requiring internet services to only be provided to people with their real names reported.
NYT keeps a feed going dedicated to the general topic here http://topics.nytimes.com/topics/news/international/countriesandterritories/china/internet_censorship/index.html
I ran my own server at home for a while (totally free Ubuntu UNIX setup on an old dilapidated Dell laptop), and found the folks in Beijing were just ahead of the ones in Virginia coming to check out my newly registered domain name. Since the IP address was dynamically generated and changed from from time to time, that did not have much to do with it.
After the Russians made a visit, the amount of spam started picking up drastically. Aksimet from Wordpress was a savior, and I can't recommend both Ubuntu (server version) and Wordpress enough. Great tools for learned how to DIY an internet presence.
In the end I switched to free hosting and serving from Wordpress.com and Redbubble for my blog and photos. This was mainly done to avoid needing to keep an eye on updates and bandwidth all the time. It is still not costing me anything up-front, but does occaisionally involve a pushed ad on my pages.