T38 reboots randomly

[_alx_]

I have a T38 unit and reboots randomly.

If it reboots, it stucks on initializing screen and doesn't finish boot up.

I tried upgrading to 38.70.0.125 and also made a factory reset but the unit worked fine for a day but it did it again.

a) Is there anything that i can try to fix this problem?
b) Also which from the following firmware is the latest because the support page is messed up

38.70.0.125
38.70.0.180
38.70.248.36
38.70.0.132

My pbx is an Elastix installation.