I have recently aquired a 2003 fabia tdi estate.

i've got problems with the abs, it engages at very low speeds intermittently. 

Its got relatively new discs and pads, brakes have been bled, calipers all checked and ok, had a new bearing, yet when it happens the ABS light doesn't flash or come on nor do any codes come up upon diagnosis. Very puzzled new Skoda owner; any advice would be appreciated 

Was it one of the front wheel bearings?

@Swain88 - I'm thinking much the same thing as @Wino , that probably the air gap on the sensor where the bearing was changed is incorrect.

yeah it was a front one, but the problem was there before the bearing change, i should have done both, but while trying to solve this problem i'm trying to save the pennies. 

The bearing was rather corroded so perhaps changing the other one MAY solve it, otherwise i'm out of ideas.