Digital BW, The Print

Hello everyone,

I hope anyone can help me with my problem: deflecting nozzles causing 
banding and noise in the prints.

There are 2 or three nozzles in the cyan position that often –not 
always- deflect the ink, which results in a Nozzle check pattern as 
can be seen at http://members.ams.chello.nl/iwesdorp/cyan/cyan.jpg 

Some remarks:
-I use Piezography ink.
-The problem started after I cleaned the printhead with a piece of 
sponge soaked in Windex. Repeating this didn't clear it.
-Regular cleaning doesn't help.
-Raising the bottles about 1/5 inch didn't help.
-Switching the printer on some hours before I start printing doesn't 
help.

And the strangest thing is that it appears and disappears randomly: I 
make a print and it is there. On the next print it is gone. And in 
the third print it can be there again. How can this happen? If the 
nozzles are partially blocked, they should always behave this way, I 
guess.

Hope anyone has the answers.

Thanks in advance.

Igor