I found out finally that it was my X rods that were bent. Same issue as described here : extruder at 0.2 mm in the center of the bed, and around 1 mm on the sides...

I changed all the carriage with the lawsy carriage, and brand new rods, and don't have any issues no more. But my machine was no more under warranty, and I bought it used.

You should check if your bed is really warped, it is probably not. My suggestion is you should ask solidoodle to replace the carriage of your machine.

Yeah that may not work for me. It is raising in the middle, not dipping. I'll contact Solidoodle about this. Thanks for the advice though. Should the bed ever dip in the future, I'll more than gladly get a piece of glass!

My personal recommendation:
*Replace the aluminum platform
*Buy a piece of glass to size said platform
*If possible, buy a reel of kapton to cover the platform before placing glass. If you have kapton, you can easily spray some extra/extreme hold hairspray onto the kapton wardjr and myself mentioned, as well as the top surface.
**If you do not use kapton on the kapton-on-aluminum+glass process, you will need said document clips and hairspray.

But if you have a bulge rather then a dip, you NEED to have to replaced. Nothing good will come from a factory defect to that level.

Azerate, as I do more research, it seems a mirror may be the best choice. Where did you get yours? Was the process of replacing the bed difficult? Which tutorials did you use, if any?

I never got a new bed. I just went to a local glass store and had them cut 2 6''x6'' mirrors (I run SD2), and slapped it on. You can either use those small document clips, or mist some hairspray (prevent said hairspray from getting onto your electronics, belts, etc) on the kapton, then put the glass on. Many users swear by this technique. Then you have to adjust your Z tab. On the SD4 I believe there is a wheel in back that you turn. This will lower the height of the tab. Since you are essentially raising the bed by 1/8", you must lower the tab to prevent any damage to your hotend.

Please bare in mind, though, that you can only do this if your bed has a dip. If your bed is raising, you will need to look at replacement which SD will honor.

When you and Ronsii say change the settings, do you mean under "Printer settings" > "Dimension" in Repetier? I have the x-max and y-max as 200 and the x-min and y-min as 0.

Azerate, as I do more research, it seems a mirror may be the best choice. Where did you get yours? Was the process of replacing the bed difficult? Which tutorials did you use, if any?

My bed warped after a month of use. Instead of waiting for SD to take their sweet time to send me a new one that I would have to fix, I just tossed on a mirror. My platform is now perfectly flat and I get superior adhesion .

I have a Solidoodle 4. I only did one test print which turned out fine (the one suggested in this article provided by Solidoodle called "How To Print")

I didn't mess with any of the settings. I've only had the printer for a week.

Here is the story: After setting up the printer with the instructions on Solidoodle's website, I did a test print, which came out fine. After that, I printed a couple of small things, which also turned out fine. A few days later, I went back to the printer and attempted to print a simple squirrel found on Thingiverse (under the collection "Get Started"). After a few layers, the left side of it would unattach from the bed and curl up. After closer investigation, I noticed that the bed was curved (the middle was higher than the left and the right). I tried to calibrate it so that it would level out (by turning the screws under the bed), but I couldn't manage the leve it out. After some research, I found out that it might be defective and that I should contact Solidoodle.

A couple of days later, I went to take a video of the print bed to prove that its curved so I could send it into Solidoodle. That's when I was moving the extruder up and down when I realized that it bumps against the left side of the printer and continuously does so if its prompted to (but it refuses to move when its all the way to the right).

Again, it's hard to explain. Please search for the video "soliforum 12b68" on YouTube.

Thanks so much for taking the time to help me.

Also...if you cannot give a direct link, at least change the video title to something unique we can easily find.