Digital BW, The Print

I am using Eboni in the Y, MK and PK positions, PKN in the C,R and B 
positions, PK is spare but has PK in it and Glop is in the Glop 
position.

I managed to get perfect nozzle checks in the positions but a couple 
of failures in the PK and MK positions.  I ran a cleaning cycle and 
lost some more nozzles tried again and the position was worse.  I 
tried again and very few nozzles fired properly.

I waited three hours.  After acouple of nozzle checks, the R, G and 
B were OK so I printed with these using QTR.

The next day I tried again and after two cycles of nozzle checks, 
cleaning and waiting three hours I was able to profile a new paper 
with the PKN inks.

This morning I am back to square 1.  I don't think I have clogs but 
bubbles caused by the aggressive cleaning regimen of this printer.  
Has ay one experienced this problem?  Has anyone resolved it?

Thanks,

Colin