So you're saying you originally had paddles that worked, now after the steering wheel install, even your stock paddles don't work?
I would say that coding might be an issue going from your original paddles to the DCT, but if even your original paddles with original MF buttons don't work, I would venture that this is not a coding issue if you never coded the car to begin with to change anything (I realize you went in there to remove the error, but you never coded the car previous to that)
Because your original setup doesn't work either - Software doesn't know what type wheel you have installed, so this sounds to be a wiring/hardware incompatibility problem. - not as if the steering wheel sends a signal to the computer stating 'Hey, I'm a M3 steering wheel'
At 1st guess I would say that it has something to do with the integration of the Paddles and the Multifunction buttons - which may be different between the wheel types, but you state you put back your original style MF Buttons and Paddles and they still didn't work?
2009 328ix E92//SGM//ACS Roof Spoiler//MTech Aero Lip+Trunk Spoiler//M3 Side Skirts//CF Roundels+Grilles//M3 Novillo Interior//Perf Shift Lever+Boot//MPerf DCT Wheel//M3 GT3 eBrake Handle+Boot//ACS Pedals//M3 Mirrors//LCI Tails w/LUX Rev//LUX 160 AE+MTec 6000K D1S+HPB HID 6000K Fogs//HPB LED Interior//RPI Scoops//CF Euro Airbox+Underhood Hsgs//K&N//BMW PE//MTech Rear Bumper-iS Sport Diffuser//CF Strut Brace//AA Stage3//BMW 193M's+Kumho 4X