RMSDK 9.1 is not happy with the CSS in SSM02.epub and emits the following errors:
W_CSS_PARSE_ERROR file:///.../SSM02.epub/OEBPS/pdlmsr.css BadSelector
W_CSS_PARSE_ERROR file:///.../OEBPS/pdlmsr.css syntax error
RMSDK 9.2 handles the files correctly (and renders both correctly). So it looks like a bug handling the text encoding format, that has been fixed (Peter could confirm this).
Unfortunately ADE 1.7 is using a fairly old version of the RMSDK 9.1 or before IIRC. Here's hoping Adobe will come up with a more modern version of ADE.