More of a ' heads-up ' than a cry for help ( at the moment! ) but I ran the available updates yeterday evening ( Sunday ) which invoved a restart. Plymouth ran as normal, but sticks on the 'f', i.e. no login screen. Had to do a power-off shutdown ( aka pulling the plug ). As the updates included a new kernel and I'm running the nVidia akmod drivers I'm suspecting no driver yet available for the new kernel. Good thing I
try to have at least two machines up and running, so I can search for ideas. Now back to the casualty and see if I can break in to the boot sequence and roll back to the last kernel. Wish me luck!
It certainly looks as if the new kernel ( 126.96.36.199-32.fc15.i686.PAE ) was the culprit in some way, I've rolled back to 188.8.131.52-30 and that boots to a login screen.