When using a clean version of D7.15 and Aurora 1.1 I get the following errors when sass compiles the susy and singularity themes.
error sass/ie.scss (Line 18: File to import not found or unreadable: partials/styleguide/ie-style-guide.)
error sass/print.scss (Line 18: File to import not found or unreadable: partials/styleguide/print-style-guide.)
It doesn't happen with the no grid theme. So specifically in the globals/base partial the problem occurs with @import 'aurora/singularity-grid' and @import 'aurora/susy-grid' but not with @import 'aurora'.