The bosch ABS module/program is custom tailored by bosch engineers for the specific car. It is optimized for the OEM parts. Any change with any parts (tires, wheels, pads) and you can throw the program off, if only by a little bit.
Many of these changes simply do not allow the easy steering while brakeing feature of ABS... in other words, you may expirence some short bursts of lockup... or may never be able to extract all the stoping power of the new tires.
