060 w/ Mediator freezes then resets

[Atlantic]

Hello, it's my first post on the forum.

I have lately acquired a 4000 system in a Micronik Big Tower equipped with a Mediator 4000D. The 060 is a Rev. 6 on a 040 to 060 adapter attached to A3640.

Previous owner told me there is something wrong with the ROM.
It has KS314 and OS39. So we thought maybe that was the problem.

I have done a clean install with an emergency disk containing 060 library. RIght after it, I could do whatever I'd like to. I have played DoomAttack and some other games.
Then I have installed MUI, Mediator drivers, MMULib (intermediate setting), BBs, IBrowse, trackers etc. And it became so unusable that a small task such as using IBrowse or even AmiFTP would make the system suddenly freeze and go into hard reset.

There are 3 things I am suspecting.

1) The Spider 2 card was pulled from a 1200 so maybe some firmware or voltage problem? I don't know much about these boards.

2) Micronik tower is vertical and A4000 is not designed to hold the adapter toasted into the CPU slot of A3640 when it's in the vertical position.

2) There is something wrong with MMULib or other libraries when used with KS314 on OS39.

I would be really glad if you'd help.

Thank you,
Sincerely yours, Atlantic