I seem to get different results and conflicts re: decimaled numbers.

Example: In SQL Server2K I have a record in a table with a field value of 388468.031 (DataType REAL) However, when I try to do a insert into that table with a PK value of 388468.024 I get an update conflict/Dup PK. Is there a setting to control rounding of decimal values? .024 and .031 are two differnt numbers.