I think I have the same problem. As the printer warms up there is a clicking noise and the paper will jam or get creased/folded on the way through.

I have had a look in the back and can see some black plastic on the fuser. This plastic is only running about 90% of the way across.

I can't tell if it is supposed to be there and has torn or something or if it isnt supposed to be there at all and has been fed in with the paper at some point?

I have the exact same problem.  Took apart the printer today, and saw what needs to be fixed (I think).  That plastic covering piece (I don't know enough to know what it is), was ripped and what was causing the paper crunching sound.  I tore off the piece that was ripped so it looks smooth, and upon startup and printing the crunching sound is dnow gone.  However, it still jams the paper and doesn't feed past that point.  It looks like it is jamming somehow on that exact section.  I think a new piece is in order, however my printer is also now out of warranty.  Anyone know what that piece is and if it can be purchased?  Here is a picture:

So I was doing a little more research, and found that it is based off the Lexmark E352dn:

http://www1.lexmark.com/products/view/Printers/Lexmark%20E352dn/catId=cat10006-category&prodId=3714-product

I don't know if it is a "fuser" or not, but apparantly those could be ordered (and might be similar?)

http://www.lexmark.ca/lexmark/product/home/488/0,6970,204812589_653399458_881502696_en,00.html?tabId=1

This might look like the fuser for the Lexmark printer - its part number is "40x2800 fuser kit":

http://www.databazaar.com/Inkjet_Cartridge/Catalog/E352dn_3086.html

http://www.fastprinters.com/ProductDetails.asp?product_id=LEX-40X2800

http://www.fastprinters.com/ProductDetails.asp?product_id=LEX-40X2847

http://www.westwoodsupplies.com/proddetail.php?prod=LEX40X2800

From the pictures, it looks like that is the part.  I'll probably order it sooner than later and see how it works out.

Yep thats the exact same thing as I had.

I went searching for the prices of replacement Fusers and in the end decided that the cost was too much. 2 Days later I got a second hand 1720dn for $60 off of ebay.

My printer does the same thing.  Started jamming alot and then it jammed and I took out the paper but the printed stills shows a jam and will not work