Dayz is going to be 64bit only so you should consider changing it, they said it in their devblog , it's not just my opinion.And apart from that most new games run on 64bit.

You say you have a 32 bit system but have 50 fps all time, so im guessing that you have a strong PC ,which means that you should play on 64 instead of 32bit. Try formating your pc and changing to 64 bit or just wait for the answer form the dev because maybe something else is causing the crash in your game. I had the same issue and changing to 64bit helped me.