MakerBot Industries

Yes, that's a well known issue with ABS. It happens due to the high rate of expansion of ABS at temp when it leaves the nozzle and then cools and shrinks at room temp. PLA is much better at not doing this. One way to fight it is overfill each layer for better bonding between layers, possibly increase the number of "shells" to 3.

In print-o-matic, change the pinch wheel diameter to a smaller number like 9 or 8 thus making the bot put down more plastic each layer. It won't be as pretty, but mechanically, it will be fine.
extra shells may cause other issues with small holes, but it looks like you can get away with 2 or 3 extra shells in the part you posted. FYI shells are extra wall layers. More wall layers equals better bonds between layers. Also, lowering layer hieght may help.

I'd say it may be because of temperature too different at the bottom layer and the following layers.
I'd try to heat the build platform up to let's say 130 degrees C (at least for the beginning of the print), try to cover the bot (for a test some cloth would suffice).

First, are you using the heated build platform or the automated platform?

Just a guess but i haven't seen warping like that since the last time I used the ABP with it's belt. If that's the case, right there is your problem-switch to HBP by removing the belt and using Kapton tape stuck to the heater PCB as shown in the directions, or better yet, get the $8 aluminum upgrade plate.

If you are using the HBP, wipe that thing down with acetone and a paper towel while it's cool and do not touch the build surface with your fingers ever. Even the slightest fingerprint will keep the first layer from sticking.

I wasn't getting warping that bad when I was using printer's tape direct on the heater while waiting for my aluminum plate and kapton tape….

What temp does it say you are extruding at? Are the smells pretty strong while you are printing? I am really thinking you may be extruding at a higher temp than needed…

Right, and it's a known fact you cannot get large parts to print with a flat bottom on the APB belt since it will lift the edges of the belt, which then lets it cool more and lift more in a feedback cycle. You MUST remove the belt and use the heater PCB covered with kapton tape.
This is the whole reason why anyone printing for very long has switched and NEVER uses the ABP again.

The ABP is a neat idea but is not practical.

use heat. ;)
the problem is most probably the ABP belt.

Try the HBP, or if you are "too lazy" for that, just remove the belt from tha ABP and put kapton tape on it.

Hmm.. I must say I'm running out of ideas. OK, let's sum it up:

-you are printing on HBP with kapton tape on it. (or with ABP with the transparent belt removed an kapton tape sticked on the aluminium foil)
-you cleaned the kapton tape with acetone prior printing
-you heat the printing bead to let's say 130 deg. C for printing (for whole printing? or just for start? did you change it in the start.gcode in your profile as well?)
-you don't have too cold room (let's say below 20 degrees C)
-you have correctly set the z-axis alignment, so the first few layers are not "smashed" together, but the first layer is printed sufficiently close to the platform in order to stick good to the platform.
-you don't have any "crazy"(like putting too much plastic) settings in skeinforge for the first layer

Hmm, somebody any more ideas what to check more?

Hmm… to bad..
One desperate last shot.
As for the skeinforge setting the "flow rate" is set correct? Don't you extrude too much material?
If you print a wall of one line does it have a desired thickness?
I don't it must be your issue, but IMHO it's time to start checking "all possible".
I'd say try to calibrate this.. following link may provide some help with that:
http://reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide#Skeinforge.2Fsfact_settings