Digital BW, The Print

I left my 1200 with MIS VM inks for 2 1/2 weeks and came back to 
clogs that will not go away, even after 9-10 cleaning cycles and a 
number of full prints.  (I use prefilled carts.)  While I know this 
topic has been covered at length on the list, I would appreciate a 
suggestion of a reasonable first step before I delve into the 
archives and go at this full tilt.

The strange thing is that there is a great deal of variation in the 
nozzle check patterns with some not all bad and other where several 
of the inks are hardly there.

Thanks for any help.

Steve