Need help setting up 3.5bar map sensor on aem

[tlicense]

All,

I've just posted this on the aem forum, but was wondering if you guys had any ideas....

I've spent all day trying to change from the stock j-spec MAP sensor to the AEM 3.5 bar sensor.
The sensor I have is part no. 35-2112.
I'm running the wizard for the 3.5 bar sensor and then rescaling the load break-points back to what they were for the stock sensor.
For good measure I've also copied the main fuel and ignition maps from the stock calibration and pasted those back onto the new one.
When I key on, I've checked the voltage of the sensor, which was about 1.6 volts, which gave a reading of about 100kpa (about atmospheric) and was approximately the same as the stock sensor.
However when I start the engine I'm getting vary strange results. The idle seems to bounce up and down within a 100 rpm or so (before it would stay within 50) and the O2 maxes out at nearly 20:1, where as before it would idle at about 15/16:1 quite nicely.
I'm starting to run out of ideas.

I'll attach both the maps and a log of about a minutes running under both conditions. If anyone has any ideas then please let me know!