  Measuring the depth variation of the meridional flows is important for
understanding the solar cycle, at least according to a number of dynamo models.
While attempting to extend the early observations of \citet{giles_thesis} of
time-distance measurements of flow, we have stumbled upon some systematic
errors that can affect these measurements: 1) the additional distance traveled
by radiation coming from points away from disk center causes an apparent
`shrinking' Sun, that is an apparent flow towards the disk center and 2) in
measurements away from the central longitude, the rotation signal can leak into
meridional flow signals. Attempts to understand and overcome these systematic
problems will be presented. Forward models based on ray theory have been
applied in order to test the sensitivity of travel times to various models.
