Digital BW, The Print

I'm having a problem with my 7500. I'll get part way through
a print 
and then it will start depositing splotches of ink on the print as it 
goes and if the splotch is big enough the head will drag ink across 
the page into the margins. It looks to be mostly the black Eboni ink. 
Any thoughts about what could be causing this? I'm using QTR with
UT 
inks. USB connection Photoshop 7. Mac G3.

John H