Canon i9900 banding

[Backroader]

I'm having a problem with banding on my i9900. It's really evident on prints larger than 8X10 inches. Occurs on all my Red River, Canon and Ilford papers.
It was banding when I was using Windows Vista and still banding with Windows 7.
All the alignment and nozzle checks indicate no problems. Banding is not indicated on the monitor nor on prints made on a friends printer.
I am using Canon inks. I current with all software and hardware updates.
Is there any hope or do I now have just a good 4X6 printer?
As I just bought a couple hundred dollars worth of ink, any suggestions would be well recieved.
Thanks

[S-Man]

Did you go a long time without using the printer?

THIS might help. Although I cringe at the thought of using so much ink...

If that doesn't clear it up, it may be time for a new head.

[Backroader]

Thanks. With the nozzle check showing no problems, I didnt think of off-printer cleaning.
I'll do it and post the results when I get back in town.
Thanks again.

[S-Man]

Yeah, definitely keep us updated.

[Backroader]

Cleaning did not work. In fact there was no change. I cleaned this head once before when I changed back to Canon inks from 3rd party a couple years ago so I'm sure I did it right.
I have another head on order. At $80, I figure it's going to be cheaper in the long run in lieu of more cleaning and testing or getting a new printer.
By the way, the printer did sit idle for about 3 to 4 weeks just before the banding started. Guess I need to run a print at least once a week for sure. Also, there is no banding in the first and last inch of print. Golly, I hope this problem is a bad head and not something in the electronics or whatever.

[Backroader]

My printer is up an runing like new. Put the new head in, re-alinged and back to it's old sharp self.

Backroader added 9 Minutes and 28 Seconds later...Double Post Merged Below

Final Note-
Thanks S-Man. I must of had a heck of a clog cause none of the cleaning procedures worked. I'll now run something through my printer weekly and just maybe I won't have to go through this again. If I do, well, new heads are cheap, fast and will surely get the job done.