Default [q] jb to ics,and umts device

My device - xt910 umts spyder
A few days back i flashed .au firmware on my mobile to get android 4.1.2 earlier i was on asiaretail android 4.0.4
but not i get many problems with it due, sometimes imei gets missing n **** .
i want to get back into my orignal firmware
Upon trying to flash back asiaretail i get signature error" failed flashing process.6/19 flash cdt.bin_signed phone returned fail"
which i think is because of either 2 reasons
1)my mobile is spyder_umts and firmware i m getting online r only spyder
2)I m trying to flast 4.0.4 on 4.1.2

kindly help me what to do ..