Ubuntu will not start

[Lenny]

Hi,
I have been running Ubuntu 10.10 live on an 8GB SD card on my Asus, using 
Orca and Eloquence.
I cannot get into Ubuntu any more,  after it spent all night running, it did 
not respond, so the next morning, and after trying the power button, which 
usually brings up the "shut-down" option and pressing enter, it did not shut 
down.  I had to do a hard shutdown, and now it will not boot up to Ubuntu.
Later when I had a reader, I found that it was able to boot, but no sound. 
I tried the normal shut down, and it shuts down, but it may, or may not boot 
up now, I can't tell, but if it is, it still has no sound for Orca.
I don't know any more how to get to the Ubuntu safe boot since I'm not sure 
if that is an option any more once the live version is put onto a USB or SD 
card.
Thanks for any help.
Glenn