A drift-tube mass-spectrometer apparatus has been used to determine the rate coefficients for the loss of O++ ions by charge transfer on collisions with N2 and O2 molecules. At 300 K the respective coefficients are (1.3¿0.3) ¿10-9 cm3/sec. Even at F-region temperatures these reactions should be fast, since the rate coefficients for reactions of this type vary only slightly with increase in temperature. However, in the recent model calculations of Breig et al, the AE measurements of the O++altitude profiles are only reproduced if the O+++N2 rate coefficient is assumed to be much smaller than 1010 cm3/sec. Thus we conclude that important sources of O++ ions have been omitted from the model.