Digital BW, The Print

I'm running a new 1280 with MIS VM and VMS cartridges.  I seem to be 
getting nozzles clogs lately.  I run a nozzle check before each run 
and usually I have to do one, two and, sometimes three cleanings to 
get it going.  The clogs seem to have gotten worse just in the last 
week or so.
I print just about every day and wonder if this is typical.  Did I 
make a mistake going to the MIS cartridges right away without running 
the Epson cartridges first?

Thanks,

Tom Husband