If your amiga was unstable and became 'more' stable after just installing fastram your chipram might be defective.
Remove the fastram from the system and run a memory test. Installing the fastram might just have reduced the chance of runninc code from a defective memory location. Hence your system became 'more' stable but is probably still somewhat unstable.
Edit; things can also be simpler focussing on the software you have running. Perhaps a log file of some sort is being maintained on your ram drive. Your machine can crash because it runs out of available memory and software is coping bady with that. Installing the additional 16M buys some time in that regard.
