I get a streak down the middle of every page that prints. I have tried cleaning the printer, even tried replacding the cartridge, but still the same persistant streak, on every page all the way from the bottom to the top.

It is possible that the cleaning blade on your toner cartridge is malfunctioning. Try replacing it.If you can time it right,try shutting down printer in middle of print job when copy is between toner and fuser and see if the problem is before it reaches the fuser.

Make sure you are inserting genuine Lexmark cartridges.
Try to clean the cartridge nozzles. Refer to the steps below:

Cleaning the Print Cartridge Nozzles:

1. Open the Lexmark Solution Center. Click Start > Programs or All Programs > Lexmark 1300 Series. Select Solution Center.

2. From the Maintenance tab, click Clean to fix horizontal streaks.

3. Click Print. A nozzle page prints, forcing ink through the nozzles to clean the clogged nozzles.

4. Print the document again to verify that print quality has improved.

Using the control panel

1. Press Menu.

2. Press the down arrow button until you highlight Clean Cartridge.

3. Press Select. A nozzle page prints, forcing ink through the nozzles to clean the clogged nozzles.

4. Print the document again to verify that print quality has improved.

Put paper in the manual feed tray. That's the pull down door in the front.
Print something. As the page gets fed 3/4 of the way into the printer, open the top cover. Pull out the toner. Look down at the paper. If you see the prominent streak, you probably have a bad toner cartridge. If the streak is not there, check the fuser. One of the rollers is bad.

While you have the toner in your hand, you should see a flap that is the entire length of the cartridge.
Put you thumb on the flap and pull it down. You will now be looking at the drum.
If you see the prominent streak, that's your problem. See if you can clean it with a soft lint free dry cloth. If the streak comes back, the rubber cleaning blade is probably bad. Replace the toner cartridge.

The drum cartridge may need replacement even if the printer isn't telling you to do so. Try printing a "config" page to see how many pages are currently on the cartridge.

Streaks (thicker lines) indicate faulty PCR Roller which is located behind the green drum inside the cartridge. As the printer has 4 cartiridges, you have to identify the faulty one. You may replace the cartridge or get the PCR Roller changed by a professional.

Let me know if any further clarification is required. Hope this helps!

CreatuiveTECH

sounds like your cartridge is leaking. I'd try replacing the cartridge

If this started after cartridge was replaced, then it is probably defective.

Take the cartridge out and take a look at the print head. Clean the print head.
Put the cartridge back in
Try and feed paper (not printing anything on it, if you can not get it to just feed paper, print a blank page) and see if it still has lines. If so, you are probably going to have to clean ink from inside the paper feed area. If not, try using it for a while and if it starts again, get a replacement cartridge. You might want to save some of the bad prints to show the clerk and try to get the new cartridge under warranty.

i took out my drum and cleaned it with alcohol and then wiped down the inside of the printer anywhere the drum touches with a towel soaked with alcohol and the did about 40 prints and it fixed my pagepro (with each of these 40 prints the the quality got better)

Streaks can be caused by a number of things
The fuser
The ETB
The toner cartridge
The firmware
The printer needs a cleaning.
The slot in the printer.
Incorrect Media.

Try cleaning the printer, use a lint-free cloth for the ETB, DO NOT touch the belt with your fingers, the oil from fingers will often make things worse.
Always use a lint-free cloth, if you ever encounter dirt inside the printer, dampen the cloth.

Calibrate the printer.
From the printer's control panel menu
Configure Device-> Print Quality-> Calibrate now.
(Press the Checkmark key to advance through menus)

It sounds like you have a clogged printerhead without seeing test page it is always abasic guide. I would thoroughly manually clean all cartridge printheads (whether on the cartridge or the unit) with cotton buds and proper cleaning solution. Try and print once you reset your ink levels. post back if no help.