Tried a hish-speed usb 2 card reader, with the same results.
I've sent the camera back to pentax now, let's see what they come up with.

Once again, thanks for all your suggestions and help

Well, thanks for all your helpful replies folks.
I did speak to Pentax and like mikew said, they just suggested sending it back.
I'm sure my PC is up to the job, I'm running win xp pro with 4 USB2 connections.
Johnriley, I'm going to try your suggestion of swapping card readers before sending it back, otherwise, like has already been mentioned, it could go back and the problem not be remedied.

Firstly, thanks for replying.
How about this then. I've always used a card reader to D/L pics but, after you mentioned that, I looked at the USB port and it's broken.
Now that poses a whole new set of questions:
Would that be my problem?
Was the USB port broken when I bought it?
If it was already broken, surely the engineer would have seen that when he/she tested it?
Oh, I'm totally confused now.
I'll phone pentax tomorrow and speak to a person I think.

thanks for the guidance

Thanks for replying.
Well, I've changed SD cards (I'm using sandisk extereme III)
I was going to change card reader next but pentax made no mention of that when we spoke. They actually said they had replaced "a part"...whatever part that was.
I'll phone tomorrow and speak to someone I think.
Thanks again for replying

just an update.
I sent the camera back to pentax and they have just returned it after carrying out a repair.
However, the problem still exists
I'm going to inquire about getting my money back. I'm afraid I'm a bit disillusioned with them now.

Once again, thanks for the reply ammonyte. The lines in other pics stay pretty central but sometimes there are less lines.
I've sent the camera back to Pentax now, so let's see what they say
Thanks again, for all your responses.

Thanks again ammonyte.
I've used a different SD card and then formatted both within the camera. I've not tried the different PC yet, so that's my next stop. The strangest thing was, that the assistant in the shop yesterday, took about 30 random pics and when I got back and transferred them to PC, not one of them had banding on them

Thanks for the reply ammonyte but the banding is horizontal, not vertical.
I never even considered the graphics/video card on the pc, so that's an avenue to pursue.
Thanks for replying

Thanks for the speedy reply Matt.
I have to be honest here and admit I've not used RAW mode at all and I use Photoshop CS2 to process the pics
and yes, the problem occurs at all ISO ratings.

The most frustrating thing is, when I took the camera back to the shop today, the assistant took about 20 pics and not one of them had any banding on them when I got back home and transferred them to PC.

It's baffling me for sure

Hello everyone,
I've been reading this board for a while now and very helpful it's been too, so I decided to take the plunge and register.
Now then, I have a problem with my K100D which, despite extensive searching, I can't seem to see any answer to.
Occasionally I get "banding" on my images. I've posted an example here in my flickr account http://farm3.static.flickr.com/2028/2065346535_30b8533e7b.jpg?v=0
This banding comes and goes and sometimes it's bad like, you see here, other times less severe. I'm using a 2gb sandisk extreme SD card and without changing any settings the next image could be fine.
I've just spoken to the person in the shop where I bought the camera from and they say it could be an image transfer problem? Perhaps I need a new card reader? I'm reluctant to send it back to Pentax (it's still under warranty) as the person in the shop reckoned it's 6 - 8wks to investigate the prob and then maybe repair. I'm going away on xmas day and wanted the camera for that, hence the reluctance.
Right, I think I've waffled enough, I do hope somebody has an idea what's going on and can help. If not, just thanks for all your previous posts that have helped in the past