first of all u should know whether ur phone uspports JSR 75. if u are sure that ur phone does support JSR 75 . then u should check why is it giving an error... this can be done by simply placing an alert in the catch statements ... running an Midlet on a simulator is totally different from when it is running on the phone....

u can also check for the permissions... should include the file permissions whils packing the midlet...

is it showing any error... u should know the error to exactly tell u the solution...

do let me know... best would be to put an alert and print the error....

catch(Exception e)
{
alert("",e,....);
alert.setTimeOut(alert.FOREVER);
display.setCurrent(alert);
}

first get to know the error and try to solve it....