  Current analyses of VLT/UVES quasar spectra disagree with the Keck/HIRES
evidence for a varying fine-structure constant, alpha. To investigate this we
introduce a simple method for calculating the minimum possible uncertainty on
Delta(alpha)/alpha for a given quasar absorber. For many absorbers in Chand et
al. (2004) and for the single-absorber constraint of Levshakov et al. (2006)
the quoted uncertainties are smaller than the minimum allowed by the UVES data.
Failure of this basic consistency test prevents reliable comparison of the UVES
and HIRES results.
