So, do you have a kickswitch or do you swap the ROMs manually?
I mean, maybe you have issues with the 3.1.4, then you can switch off-switch over to 2.x-restart the machine and if in this immediate change the problems persists it is not the ROM.
Just an idea...
If the ROM chip gets hot, it might be the wrong EPROM type with 'hanging' or otherwise wrong adressed pins.