Hi Alex, Thanks for posting. Here < http://cubeowner.com/kbase/index.php?page=index_v2&id=25&c=1 > you can read why pressing the CUDA button seems to be so important after a CPU upgrade. It resets the logic board. Besides, I've read somewhere sometime that not doing this temporarilly killed somebody's ethernet/USB/FireWire ports. That's just why I asked about your personal experience. Did you or did you not pressed it after upgrading? Thank you, LM >>> alexmay at lineone.net - 2004/06/02 10:29 AM >>> Is that the internal 'S1' button? Why is that so important?! Alex