Digital BW, The Print

Hello printers,
I got the new Inkset from MIS 2 days ago, I loaded it to virgin 
catridges. I used the cleaning catridges and purged the Epson-inks 
until it vanished from the paper,... oboy did that took long time!! 
I used 75 A3 sized plain paper to finish it off, and then used the 
backside to get in the new UltraTone (all together 150 A3's) this 
tubeees is collecting alot of inks. Anyway everything looks fine 
after a 8-10 cleaningcycles and purgepattern printings.....but there 
is some concerns about the black eboni, and it troubles me. It 
cloggs!! I've done a fair amount of cleaning even with the printer 
software (ADJ: Clean head from the servicemanual). All inks prints 
perfect except for the Eboni, when printing the purgepattern it 
print well for the first 1/4 and then it starts with banding (white 
stripes), next I do another testprint and it shows a different 
result now with much less white stripes and only on the edges of the 
black pattern. OK hold on... I do another testprint as it goes in 
the right direction...well nooo good it got worse again, I also did 
a nozzle check and find a bad one so I went for one more cleaning 
(11th), nozzle check perfect again!!... New testprint to go (I'm 
glad I got the pintsize bottles)the first 1/5-4 prints beautiful 
(black pattern) and then the stripes comes back again and it is 
confirmed with nozzel check, another clogg. I'm asking if anyone 
have any idea to get past this point. It seems like I need a couple 
of cleaningcycles during a printingsession, print part of the image 
do cleaning and continue print next part of the image. It seems like 
the nozzles only can hold clear for a few minutes, I should say 
seconds during printing until it cloggs. Would the 7000 driver be 
better could it help?(Paul use 7000 driver I guess for his 7500) As 
I'm using the 7500 driver. Advices would be greatful.

Regards
Soren