public method PutField.write throws exception in 1.4, which breaks compatibility between 1.3 and 1.4 versions. There is no sing in javadoc for 1.3 that preferred method is oos.writeFields and not pf.write. So, applications that were written correctly and run on 1.3 will not run on 1.4, which is major problem.
Moreover, method is not deprecated correctly.