Digital BW, The Print

Hi folks.  I have had no problems other than my teething VM-UT clogs 
with my Epson 1290 and MIS VM inks.
Now, after 14 months, my prints are looking dodgy.
I have very tiny banding (in direction of print head)in the mid 
tones, which is also throwing my curves out.
Obviously I have been through the usual nozzles check, all is fine.
Head aligment was WAY off and unstable.  Each time it was different.  
i think this was due to the movement of the CFS cartridges in the 
holder.  I have packed some card in in addition to the felt disks, 
things are now more solid and the head alignment more repeatable.
I have tried this on more than one paper, it shows up worst on my 
imajet paper (glasssmooth, bright white matt - UK only I think), but 
it does show up on EAM too - I think the dot gain is higher here so 
it is not AS bad.
The bands can also be seen DURING head alignment in the left hand row 
of squares, but NOT in the RHS.  I have gone from extreme to extreme 
on the alignment (I find it SO hard with the grey inks to know what 
is aligned and what is not - any advice greatly appreciated) and it 
does not get rid of the lines in the alignment squares.  Print res 
doesn't seem to make any difference and Epson service have confirmed 
that the cost of an 'out of warranty' service is almost as much as a 
new printer!  I have not really used this too much, only for my 
personal portfolio work - not on a professional basis so I'm loathe 
to bin it as a consumable, they should last longer than the warranty 
period!
Now I'm stumped and can't live with the lines now I know they're 
there.  
Any help guys?
thanks

Steve