hp 4si smearing

To use someone else's description that I saw, it looks like the Shroud of Turin on both sides of the paper when it comes through the printer. I would like to think that it is the toner, but I do not know. If I print blank pages, it still has the marks. I vacuumed the printer out and vacuumed the toner cartridge itself. There was build up on the drum itself and a pile of toner in the space that is between the drum and what I would call a transfer wheel in the cartridge. I ran a test page and it came out great, but after about 4-5 pages it had the same problem. And that space in the cartridge was full again. Are there any other causes of this? I do not have a spare toner cartridge around to easily test the unit.

Am I on the right track, or are there other things I am overlooking?

Thanks,
Brian