Without any changes to the hardware (Core Duo 2, Gigabyte G31M-ES2L, 2GB Mem), a previously flawlessly working Lion 10.7.2 install has stopped working. I get to the log in screen where the cursor blinks but I cant type anything.
I "borrowed" another Lion installation from my other PC (i5 2500K), put that on an external hard disk, it loaded alright, got to the desktop, but again no mouse clicks possible (mouse was moving though!), no keyboard response.
I booted into an old Snow Leopard installation I have on another partition, all working fine.

I wonder what could be the problem!