[Cube] Problems with Powerlogix Upgrade 1.35 GHz - yout too?

[Stefan]

Hello friends,

after a long time of waiting I decided to buy a Powerlogix 100 1.3 
GHz 7457 Upgrade.

Nervous and with a feeling like christmas I waited and built it into my cube.
In fact: about 3x times faster than my 450 MHz CPU I could measure 
with Xbench. Heureka!!!

But than the problems began: crashes, defect and even dead harddisks 
followed and so on.

Be sure, I did everything like the instructions told me. Three days 
and tow defect HDs later I ask myself, what might be the reason.
So I couldn't install more than 10.3: 10.3.2.dmg couldn't be mounted, 
same with installation of other software. (I made a clean install, 
therefore I can't imagine, that owner rights or preferences can be 
the reason...)

As I remarked, my cube had and has Boot ROM Version 4.1.9 "f".
No, back to 450 MHz, my cube works stable again.
I'm quite sure, the CPU is OK. In fact it

Has anybody of you had similar problems?

Very interested
Stefan