Digital BW, The Print

Hi-
I have an Epson 1200 with MIS Sepia installed and its been working fine 
until just lately when it has begun "banging around' as I call it.  No 
matter what I try it VERY OFTEN (now) stops at the edge of whatever 
size paper I have in the printer and retreats quickly as if it 'hit' 
the edge of the paper--- then bangs back and forth before ejecting the 
paper or printing the image shifted to one side.  Anyone know what this 
is? OR, what I can do to correct it?  Doesn't matter whether I have the 
plus/minus lever in either position.  It is as if the head is sticking 
out and hitting something but I don't see anything that could be 
causing this?  Very curious?

Thanks, Richard