I have been working my way through a Series of tutorials by sybex and I am now on chapter ten.  "Generating elevations".  I have been at this for a few months and things seem to be going well, until now.  I don't seem to be able to draw either arcs or circles in the current drawing.  I am supposed to use an intersection snap and input a circle that has an 12" radius.  The little radial arm sticks out but no circle.  I can draw an circle in a new drawing as long as the current drawing is closed.  I have considered doing this and importing it but that will answer my question.  This drawing did crash a few evenings ago when I had too many background things happening on this machine.  I can draw straight lines and clouds but no arcs or circles.What gives?S

 
 After it has done crash according to your text below.
 :This drawing did crash a few evenings ago when I had too many background things happening on this machine.
 
What see in your screen?
 
 

I see very faint green text. It is very hard to read. This is a different machine than the other one.