Failure when updating MD4 application remotely using G2 modem

We have a system that has an MD4 and two MC3 modules connected to a G2 Modem. When we update the system the MC3s get updated first which normally goes OK, but when the MD4 comes to update it always fails. We get the usual blue screen with progress percentage displayed on the MD4 as we remotely update but the MD4 screen always freezes and IQAN Design crashes out eventually. I'm assuming the size of the application file is a contributing factor because when an MD4 gets added to the application it jumps into Mb size. Is there any way of reducing the size of the application file or finding out why it crashes?

If it crashes like this its virtually renders the modem useless on an application with an MD4. The issue I have described above is only downloading a new application file, remotely updating the firmware would be even greater quantity of data to transfer remotely. Im still yet to successfully update a system with an MD4. We are running on the 02 network and the signal strength was excellent in the area.