Problem on JAR on Sony Ericsson

Hi All,I develop a mobile application using J2ME and created a JAR File. When i copied to the Nokia Mobiles [Models 2670,5300] its working fine.But if i copied it in SOny Ericssion [Model k310i,K510i,K750i,W530], it asks for Install. When i click install. It PRocess for few seconds and shows an error message as "Operation Failed".How to use my app in these kind of devices?Thank u in Advance..