Invalid Jar Error (E50 / E65)

[Quickstinger]

ok so im having a bit of a nightmare with my application, it seems to download and install (OTA) on some devices (Nokia 6230i) but for the Nokia E65 and two Nokia E50 devices I get a Invalid Jar message after it has downloaded the jar.

I have installed previous versions (1.3.6 is the last successful version that installed) of the application on one of the E50's and also the E65, the other E50 is 'clean' and has never had the application on.

all of them give the invalid jar error with the last two releases (1.3.7 and 1.3.8)

I am creating the application in Eclipse with J2MEPolish

the application is unsigned

the size of the jar matches what is in the jad

the jad information is:

MIDlet-Name: FieldCell
MIDlet-Version: 1.3.8
MIDlet-Vendor: Field Solutions Ltd
MIDlet-Jar-URL: *removed to avoid spam*
MIDlet-Jar-Size: 328126
MIDlet-Description: Field Solutions J2ME Calculator
MIDlet-Icon: /icon2.png
MIDlet-Info-URL: *removed to avoid spam*
MIDlet-1: FieldCell,/icon2.png,FieldCellMIDlet
MIDlet-Delete-Confirm: Do you really want to delete this application?

I found a Manifest file as well as i have seen people ask for it also (hope its the right one):

Manifest-Version: 1.0
Main-Class: com.fslimited.javaphone.main.FieldCellMIDlet
MIDlet-Name: FieldCell
MIDlet-Version: 1.3.8
MIDlet-Vendor: Field Solutions Ltd
MIDlet-Description: Field Solutions J2ME Calculator
MIDlet-Icon: /icon2.png
MIDlet-Info-URL: *removed to avoid spam*
MIDlet-1: ,,
MIDlet-Delete-Confirm: Do you really want to delete this application?
MicroEdition-Configuration: CLDC-1.1
MicroEdition-Profile: MIDP-2.0
Polish-Version: 2.0-RC4



any help would be very much appreciated as I am now completely stuck and not sure how to fix .