We performed an empirical study of the relation between technical quality of software products and the defect resolution performance of their maintainers. In particular, we tested the hypothesis that ratings for source code maintainability, as employed by the SIG quality model, are correlated with ratings for defect resolution speed. This study revealed that all but one of the metrics of the SIG quality model show significant positive correlation Preprint accepted for publication in the proceedings of the 4th International Workshop on Software Quality and Maintainability (SQM 2010), Madrid (Spain) 15-18 March, 2010