Digital BW, The Print

I was blisfully printing over the weekend.
Then 2/3's of the way through a long print inktone dropped off, as 
though it wasn't exposed enough.

Today I get a communications error message (& don't know how to 
resolve it).

Clues?

Using Win98se, 1270 via USB to it's own slot direct to tower, with 
MIS VM inks.  Also have a C80 attached to it's own slot in the tower -
 tried turning that off and printing but to no avail.

TIA,

Cleavis