When I run AIBB or Sysinfo the MMU status is OFF.
Don't trust AIBB or SysInfo for 68040 or 68060 CPU info.
On properly set up 68040/68060 system MMU is always enabled.
I got multiple recoverable alerts 0100 000F (task 7800ca58) on bootup which froze and crashed eventually.
This means something is calling FreeMem with bogus pointer (AN_BadFreeAddr). Try booting with clean system (clean AmigaOS install + correct 68040 libs). If that works your current AmigaOS install is messed up somehow (possibly by some library or app that gets loaded at startup).
If you get crashes even with clean AmigaOS system, then it might be hw related problem. If so, I'd suggest starting by checking for bad SIMM(s).
