ABS problems - maybe bad alternator?

Hello

So I just finished my other ABS thread. Had a  fault code 16885 - implausible signal from left wheel speed sensor. In the end it turned out that the problem was a faulty ABS module. Replaced the module, ABS lights turned of, and problem dissapeard. Great!! but it was a shortlived happiness

A new problem arose - whenever I am driving really slow,, and the activate the brake, that slow driving sets of the ABS system. The ABS lights does not come on. The only thing activated is the ABS system - you can hear it working. When I drive faster and brake, there is no problem. I wrote the guy who sold me the "refurbished" ABS module, and he suggested it might be a bad alternator causing the problems - that the alternator would cause "waves" in the current that it produces.

Does anybody have any expericence with this??? (It is a Skoda Fabia Estate 2004 AZQ)

Regards, Søren