TukeyHSD

Hello,

for some reason TukeyHSD() seems not to want to play with aov-results
with an Error() function:

Res1<-aov(H2O~location+topo+horizon+pF+Error(location:topo:horizon))
TukeyHSD(Res1, "topo")

Error in TukeyHSD(Res1, "topo") : no applicable method for "TukeyHSD"


However you could do it by hand by doing all pairwise comparisons and
adapt the confidence interval with Tukey or Scheffe. 
Or do I make a statistical thinking error?

Thanks,

Wouter