  We report on the contributions to the nucleon weak magnetic and electric form
factors arising from isospin-breaking form factors. The relativized quark model
used in the calculations includes isospin impurities in the large basis nucleon
wavefunctions and uses constituent quark currents with both Pauli and Dirac
components. Significant contributions are found to arise from the Pauli
component when it is interpreted as arising from pion-baryon loops. Including
these pion cloud contributions reduces the strange magnetic form factor
extracted from the recent SAMPLE measurement of the proton's weak neutral
magnetic form factor at low Q^2 by 35 to 52%.
