I obtained my b1b2 visa on July 2007 with multiple entry and valid for 10 years. I travelled to USA on November 2007 and stay their for 2 weeks. I am planning to visit again my relatives this year but I heard from the people around me that my visa is already cancelled since I wasnt able to re enter USA after 2 years, they said that the requirements for me to do to keep my visa active is to enter USA every 2 years.
There is no requirement that you enter every two years. I see no issue with your travel.