Is there an association between environmental and mutational robustness?
Hansen (2006) says (middle of page 140):


  A link between genetic and environmental robustness is plausible, because genetic en environmental disturbances may often affect the same functional pathways in the organism, and ny increase in the robustness of a pathway leads to both genetic and environmental canalization. Evidence for a correlation between environmental and genetic robustness has been fund in studies of RNA folding (Ancel &amp; Fontana 2000), in the effects of heat-shock proteins (Stearns et al. 1995).


He also cites Rifkin et al. (2005) who also showed evidence for this correlation. Finally Hansen cites Dworkin (2005) who did not find this link.

Hansen does not cite any theoretical paper and does not offer clear arguments of why this link exist but it is the best I could find