On the basis of suspicions raised during analysis of VSOP Survey data, a direct comparison of the ground-based visibilities produced by each of the three VSOP correlators for a single observation (observed with the VLBA, EB and HALCA) has been conducted. The residual phases after fringe-fitting agree very well, however the Mitaka and Penticton amplitudes differed substantially. Penticton has confirmed that a multiplicative factor of sqrt(2) is required for their data, and Mitaka data requires a multiplicative factor of 1.13, a quantization correction which heretofore has not been applied. With these corrections, Mitaka and Penticton agree to within 1%. These corrected amplitudes still differ from the VLBA by about 7%. Investigation of this remaining discrepancy is continuing, with one possibility being that the difference may have been introduced in the copying process required to perform the comparison. More details will be available from this page in the very near future.