Sec.237a US immigration act?

grand larceny conviction in 1996, got 3yr "suspended" sentence, in 2010 immigration judge classifies as C.I.M.T. and offers voluntary departure. couldnt find an attorney to take case so i ended up accepting V.D.. now have found INA sec.237a, which says that a "single" C.I.M.T. has to be committed "within" 10yrs of gaining LPR. but I recieved LPR in 1975, so shouldnt i have been outside of removal proceeding timetable according to the INA sec. guidelines? had no other criminal convictions either!!