During the years, i have encountered numerous foreigners with Chinese visa problems, they either not familiar with the new regulations here or missed the date of their registration. so in order to get a good record, register with the local police station once you settled down in China, within the first 24 hours of your arrival.
However, if you have any problems renewing or in exchange of your visa, you may write me an email for advice, i have been dealing with VISA extention and exchange between L, F. Z. for years. Every year I help around 100 foreign businessmen and students with their visa issues and have gained a reknowned reputation in the business.
so feel free to contact me for advice, and hope all of you could enjoy a pleasant trip in China!