Now i know this sounds daft but i have the same issue as the OP and have managed to fix it. I got some toilet paper and cut it to the shape of a sim card about 6 layers thick, put the battery on top and booted it up, so far a month without the problem popping up where as i used to have it daily.

I may not know how to do the coding for this phone (or even enter one for that matter) but please at least humour me and give this a try