  Neutralino dark matter leads to the formation of numerous earth mass dark
matter haloes at redshifts z\approx 60 (Diemand et al. 2005). These abundant
CDM micro-haloes have cuspy density profiles that can easily withstand the
Galactic tidal field at the solar radius. Zhao, Taylor, Silk & Hooper
(astro-ph/0502049) concluded that ``...the majority of dark matter
substructures with masses \sim 10^{-6}M_o will be tidally disrupted due to
interactions with stars in the Galactic halo''. However these authors assumed a
halo density of stars that is at least an order of magnitude higher than
observed. We show that the appropriate application of the impulse approximation
is to the regime of multiple encounters, not single disruptive events as
adopted by Zhao et al., which leads to a survival time of several Hubble times.
Therefore we do not expect the tidal heating by Galactic stars to affect the
abundance of micro-haloes. Disk crossing will cause some mass loss but the
central cores are likely to survive and could be detected as gamma-ray sources
with proper motions of several arc minutes per year.
